CONCRETE  SILOS 


Their  Advantages 
Different  Types 
How  to  Build  Them 


By 
E.  S.  H,ANSON 

Affiliated    Member    Western    Society    of    Engineers,    Editor    THE 

CEMENT  ERA.     Author  "Cement  Pipe  and  Tile,"  "Concrete 

Roads   and   Pavements,"   Etc. 


CHICAGO 

THE  CEMENT  ERA  PUBLISHING  COMPANY 
1916 


Copyright  1915 
By   The   Cement  Era  Publishing   Company 


PREFACE. 

In  this  volume  the  author  has  attempted  to  bring 
together  everything  of  value  pertaining  to  the  latest 
concrete  silo  construction.  His  investigation  of  the 
subject  has  led  him  to  believe  that  there  is  a  demand 
for  such  a  book.  While  there  is  a  large  mass  of 
literature  on  concrete  silos  extant,  practically  every 
piece  of  such  printed  matter  is  prepared  with  special 
emphasis  on  some  particular  type  of  construction,  or  on 
some  particular  phase  of  the  subject. 

This  volume  is  an  attempt  to  bring  together  all  the 
best  things  in  this  scattered  literature,  making  it,  so 
far  as  possible,  a  complete  compendium  of  concrete  silo 
construction.  For  this  purpose  the  author  has  drawn 
freely  upon  bulletins  of  the  various  cement  companies 
and  of  the  Association  of  American  Portland  Cement 
Manufacturers,  as  well  as  upon  publications  of  the 
State  Agricultural  Experimental  Stations,  and  the 
literature  of  the  companies  promoting  various  patented 
systems. 

The  demand  for  the  book,  even  before  it  has 
appeared  from  the  press,  has  been  so  gratifying  that  it 
is  expected  another  edition  will  be  necessary  at  an 
early  date.  The  author  will  therefore  be  pleased  to 
have  readers  advise  him  of  any  errors,  inaccuracies,  or 
omissions  which  they  find. 

E.  S.  HANSON. 
Chicago,  Oct.  15,  1915. 


365551 


CONTENTS 


Page 

Chapter  I.  Why  Build  a  Silo 5 

"  II.  What  a  Good  Silo  Should  Be 25 

11  III.  How  Concrete  Meets  the  Eequirements 30 

"  IV.  Advantage  Over  Other  Kinds  of  Silos 37 

1 '  V.  Size  and  Shape  of  a  Silo 49 

11  VI.  The  Different  Types  of  Concrete  Silos 56 

' '  VII.  The  Foundation  of  the  Silo 59 

11  VIII.  The  Monolithic  Silo 63 

< '  IX.  The  Polk  System 73 

' '  X.  The  Monsco  System 79 

"  XI.  The  Eeichert  System 84 

' '  XII.  Other  Monolithic  Systems 89 

"  XIII.  The  Pit  Silo 97 

XIV.  The  Metal  Lath  Silo 102 

"  XV.  The  Concrete  Stave  Silo 125 

XVI.  The  Concrete  Block  Silo 140 

' '  XVII.  Doorways,  Doors,  Eoofs,  etc 157 

' '  XVIII.  How  to  Increase  the  Silo  Business 165 

Catalog  Section 175 


Concrete  Silos 


CHAPTER  I 

WHY  BUILD  A  SILO  ? 

The  silo  is  not  a  fad.  It  has  proven  its  right  to  a 
place  in  any  intelligent  scheme  of  agricultural  econom- 
ics, and  it  has  therefore  come  to  stay. 

Coming  first  into  existence  as  a  mere  hole  in  the 
ground,  the  silo  has  developed  into  a  structure  on  which 
it  is  worth  while  to  expend  engineering  ability  and 
architectural  skill.  Many  things  have  been  attributed 
to  Caesar  and  his  strategists  as  the  result  of  military 
necessity  in  the  prosecution  of  his  famous  campaigns. 
Some  of  these  are  recorded  in  his  own  Commentaries, 
while  others  have  perhaps  a  less  stable  historical  foun- 
dation on  which  to  rest.  Our  reading  of  the  Seven 
Books  is  too  far  in  the  past  to  allow  of  a  definite  state- 
ment as  to  whether  the  famous  general  himself  records 
the  use  of  pit  silos  for  the  preservation  of  forage  along 
his  lines  of  march;  but  such  have  been  attributed  to 
him,  and  the  statement  sounds  plausible,  at  any  rate. 

The  silo  has  been  likened  to  a  giant  fruit  jar.  Ap- 
parently this  idea,  too,  is  not  a  new  one,  for  it  is  stated 
that  the  early  Egyptians,  many  years  before  the  Chris- 
tian era,  put  a  part  of  their  crops  in  large  stone  jars 
for  preservation,  covering  them  as  tightly  as  possible 
to  exclude  the  air.  The  Mound  Builders  and  other 

(5) 


6%'  -Concrete  Silos 

(prehistoric  tribes  adopted  similar  expedients,  as  is 
proven  by  the  relics  which  are  unearthed  from  time  to 
time,  while  some  of  the  barbaric  tribes  of  the  present 
day  build  circular  bins  of  interwoven  reeds  and  plaster 
them  on  both  sides  with  clay,  with  a  thatched  roof  for 
a  cover. 

The  following  reasons  for  the  popularity  of  silage 
are  given  by  T.  E.  Woodward,  of  the  Dairy  Division 
of  the  U.  S.  Department  of  Agriculture : 

(1)  Silage  is  the  best  and  cheapest  form  in  which 
a  succulent  feed  can  be  provided  for  winter  use. 

(2)  An  acre  of  corn  can  be  placed  in  the  silo  at  a 
cost  not  exceeding  that  of  shocking,  husking,  grind- 
ing and  shredding. 

(3)  Crops  can  be  put  into  the  silo  during  weather 
that  could  not  be  utilized  in  making  hay  or  curing  fod- 
der; in  some  localities  this  is  an  important  considera- 
tion. 

(4)  A  given  amount  of  corn  in  the  form  of  silage 
will  produce  more  milk  than  the  same  amount  when 
shocked  and  dried. 

(5)  There  is  less  waste  in  feeding  silage  than  in 
feeding  fodder.     Good  silage  properly  fed  is  all  con- 
sumed. 

(6)  Silage  is  very  palatable. 

(7)  Silage,  like  other  succulent  feeds,  has  a  bene- 
ficial effect  upon  the  digestive  organs. 

(8)  More  stock  can  be  kept  on  a  given  area  of 
land  when  silage  is  the  basis  of  the  ration. 

(9)  On  account  of  the  smaller  cost  for  labor,  silage 
can  be  used  for  supplementing  pastures  more  econom- 
ically  than    can    soiling    crops,    unless    only    a    small 
amount  of  supplementary  feed  is  required. 

(10)  Converting  the  corn  crop  into  silage  clears 
the  land  and  leaves  it  ready  for  another  crop  sooner 
than  if  the  corn  is  shocked  and  husked. 


Concrete  Silos  7 

Another  and  even  longer  list  of  advantages  of  en- 
silage is  given  by  the  experts  of  the  Missouri  Agricul- 
tural Experiment  Station.  They  are  as  follows : 

(1)  Harvesting  corn  as  silage  saves  from  35  to  40 
per  cent  of  the  crop  that  would  otherwise  be  wasted. 

(2)  Silage  adds  palatableness  to  the  ration. 

(3)  Silage  adds  succulency  to  the  ration. 

(4)  Silage  serves  to  keep  the  digestive  tracts  of 
animals  in  good  condition. 

(5)  Silage  replaces  high-priced  hay. 

(6)  Silage  serves  to  cheapen  the  ration. 

(7)  When  silage  is  fed,  more  feed  is  eaten,  hence 
more  manure. 

(8)  The    man   who   feeds    silage   uses    a   manure 
spreader. 

(9)  The  feeding  of  silage  means  more  intelligence 
in  feeding  operations. 

(10)  The  feeding  of  silage  results  in  more  intelli- 
gence in  other  farm  operations. 

(11)  The  man  who  feeds  silage  will  feed  with  it 
concentrates  rich  in  protein,  and  leguminous  hay  of 
some  kind.    Hence,  not  only  more  manure,  but  a  bet- 
ter quality. 

(12)  The  man  who  feeds  concentrates  and  legu- 
minous hays  with  silage  is  apt  to  try  to  grow  legumes 
in  the  rotation.    Hence,  a  better  and  more  productive 
soil. 

(13)  Silage  is  a  good  feed  for  the  general  farmer. 

(14)  Silage  is  a  good  feed  for  dairy  cows. 

(15)  Beef    can   be    produced    more    economically 
when  silage  forms  a  part  of  the  ration. 

(16)  Silage  is  a  good  feed  for  calves  and  stocker 
cattle. 

(17)  Silage  is  a  good  feed  for  breeding  cattle. 

(18)  Silage  is  a  good  feed  for  fattening  lambs. 

(19)  Silage  is  a  good  feed  as  a  part  ration  for 
brood  ewes  if  fed  intelligently. 

(20)  Silage  can  be  fed  successfully  as  a  part  ration 
to  mules. 


8  Concrete  Silos 

(21)  Silage  can  be  fed  successfully  as  a  part  ra- 
tion for  horses. 

(22)  Silage  may  be  fed  as  a  conditioner  to  swine 
in  general,  and  as  a  part  ration  to  old  brood  sows. 

(23)  Silage  mixed  with  wheat  and  potatoes,  equal 
parts,  and  boiled  in  water  makes  a  good  ration  for 
poultry. 

(24)  Silage  takes  up  less  room  in  storage  than 
either  hay  or  corn  fodder. 

As  to  the  kind  of  crops  which  can  be  preserved  in 
the  silo  to  advantage,  it  has  been  stated  that  anything 
which  does  not  have  a  hollow  stem  will  make  good 
silage.  This  statement  has  a  reasonable  measure  of 
truth.  The  reason  that  crops  with  hollow  stems  have 
been  excluded  is,  that  it  is  impossible  to  get  the  air 
pressed  out  of  the  stems,  and  on  account  of  the  pres- 
ence of  this  air,  decomposition  is  sure  to  take  place. 

The  fact  remains,  however,  that  corn  is  pre-emi- 
nently the  crop  for  the  silo.  As  stated  by  Prof.  C.  H. 
Eckles,  of  the  Missouri  Experiment  Station,  and  borne 
out  by  the  statements  of  many  other  authorities,  the 
total  yield  of  nutrients  per  acre  with  this  crop  is  greater 
than  ordinarily  secured  from  any  other.  It  has  the 
further  advantage  of  packing  well  to  exclude  the  air, 
and  contains  the  proper  amount  of  sugar  to  form  acids 
needed  to  preserve  without  becoming  sour. 

An  a/ere  of  corn  as  silage  requires  much  less  room 
for  storage  than  an  acre  of  corn  harvested  in  any  other 
way.  When  the  harvesting  is  done  the  work  is  mainly 
over.  The  field  is  left  clear  for  any  fall  sowing.  Drilled 
corn  yielding  75  bushels  to  the  acre,  when  cut  and 
shocked,  eleven  shocks  to  the  -acre,  covers  about  3  per 
cent  of  the  area  of  the  field.  The  shocks  remain  in  the 
way  of  the  next  crop.  Before  the  corn  is  husked  out, 
bad,  rainy,  snowy  weather  often  comes.  The  stalks, 


Concrete  Silos 


Two  of  the  Four  Silos  on  the  Dairy  Farm  of  Thomas  A.  Edison, 
at  Stewartsville,  N.  J. 

blades  and  shuck  become  so  damaged  from  the  weather 
that  they  are  not  worth  much  as  a  feed,  even  if  they 
were  always  fed  in  a  dry,  clean  place  where  stock 
could  not  tramp  them  into  the  ground  in  wet,  muddy 
weather.  The  process  of  husking,  throwing  the  corn 
011  the  ground,  pitching  it  into  a  wagon  and  out  again, 
and  then  out  of  the  crib  into  the  same  wagon  before 
it  can  be  fed,  is  not  only  an  expensive  one,  making  the 
farm  labor  problem  still  harder  to  solve,  but  it  is  a 
wasteful  one.  Much  corn  damages  from  the  weather, 


10  Concrete  Silos 

from  rats  and  mice  and  from  shelling  in  handling  so 
many  times. 

It  costs  on  an  average  about  12%  cents  to  put  corn 
into  the  shock  and  about  12%  cents  to  shuck  it  out. 
The  stover  (stalk  without  the  ear),  sells  on  the  average 
for  about  12%  cents  a  shock.  This  is  an  expensive 
operation,  even  when  it  is  the  last  resort,  but  on  some 
farms  it  is  a  common  practice. 

However,  when  a  man  has  no  silo  in  which  to  har- 
vest corn  and  his  crop  rotation  is  such  that  corn  is  to 
be  followed  by  wheat,  or  some  other  fall  sowing,  about 
the  only  thing  he  can  do  is  to  cut  the  corn  and  put  it 
into  the  shock.  This  is  especially  true  if  a  man  is  a 
grain  farmer  and  cannot  forage  the  corn  off. 

Again  it  may  be  stated  that  while  silage  can  be  fed 
to  practically  all  farm  animals  to  good  advantage,  it  is 
pre-eminently  the  ideal  ration  for  cattle,  and  especially 
the  dairy  cow.  It  thus  forms  an  important  link  in 
connecting  up  one  of  our  largest  farm  crops  with  the 
wide-spread  and  important  industry  of  cattle  raising 
and  dairying. 

The  digestive  organs  of  animals  that  chew  the  cud 
are  so  formed  as  to  require  comparatively  juicy  and 
bulky  food.  The  cow  cannot,  therefore,  thrive  on  ex- 
clusively dry  food  so  well  as  can  the  horse.  The  near- 
est an  ideal  food  that  can  be  obtained  for  the  dairy 
cow  is  good  pasture;  but  for  more  than  six  months  in 
the  year  green  pasture  is  not  available  in  large  sec- 
tions of  this  country.  The  best  substitutes  to  use  dur- 
ing this  period  are  corn  silage  and  such  roots  as  man- 
gels and  turnips.  Corn  yields  an  average  of  twice  as 
much  dry  matter  per  acre  as  do  root  crops,  and,  since 
the  latter  require  much  more  labor,  which  in  this 


Concrete  Silos  11 

country  is  relatively  expensive,  silage  is  far  more 
economical. 

The  dairy  cow  has  been  likened  unto  a  factory — a 
factory  for  the  production  of  milk  and  butter.  She 
eats  her  feed,  converts  it  into  blood  and  from  the  blood 
which  passes  through  the  mammary  gland  or  udder, 
she  extracts  the  milk.  The  output  of  this  factory,  like 
that  of  any  other  factory,  depends  much  upon  the 
amount  and  quality  of  raw  material  consumed.  No 
cow  can  produce  a  large  quantity  of  milk  and  butter 
unless  she  has  the  capacity  and  consumes  a  large  quan- 
tity of  good  feed.  Since  it  is  impossible  to  feed  fat 
into  milk  or  change  the  .average  per  cent  of  butter  fat 
in  a  cow's  milk  by  the  kind,  amount  or  quality  of  feed, 
the  thing  for  us  to  do  is  to  feed  her  in  such  a  way  as 
to  enable  her  to  produce  the  maximum  amount  of  milk. 
From  more  milk  we  can  get  more  butter  fat. 

In  order  to  get  a  cow  to  consume  large  quantities 
of  feed,  the  feed  must  be  good  and  palatable.  Pala- 
tableness  means  much.  Every  feeder  of  live  stock  of 
any  kind  recognizes  the  importance  of  keeping  the  ap- 
petites of  animals  good. 

During  the  process  of  fermentation  of  silage  in  the 
silo,  the  corn  plant  is  rendered  more  digestible  and 
more  palatable  than  dry  shock  corn,  and  a  flavor  very 
acceptable  to  dairy  cows  is  produced.  After  cows  have 
been  fed  silage,  they  will  stretch  out  their  backs  and 
turn  their  heads  in  the  direction  of  the  feeder  the  min- 
ute he  starts  toward  them  with  a  box  of  silage.  So 
well  do  eows  relish  silage,  they  will  eat  more  of  it 
than  they  do  of  dry  fodder  or  even  of  green  corn.  This 
is  a  point  in  favor  of  silage,  because  every  cow  must 
eat  so  much  feed  for  the  daily  maintenance  of  her 
body.  After  this  maintenance  requirement  is  met,  all 


12  Concrete  Silos 

excess  food  can  be  used  for  the  production  of  milk  and 
butter.  However,  some  cows  do  not  make  use  of  this 
excess  food  in  this  way.  They  use  it  for  surplus  fat 
and  flesh,  thereby  gaining  in  weight.  The  chief  dif- 
ference between  dairy  cows  is  shown  in  the  difference 
in  the  disposition  that  they  make  of  their  food  over 
and  above  that  required  for  maintenance.  Now,  if 
every  cow  would  absolutely  refuse  to  produce  a  drop 
of  milk  until  after  her  daily  body  maintenance  require- 
ments were  met,  some  of  us  would  learn  a  little  faster 
how  to  feed  for  milk  production.  But  not  every,  or 
even  any  cow,  makes  this  demand.  There  are  three 
classes  of  cows  when  both  cows  and  the  feed  they  are 
given  are  considered : 

Class  1.  Cows  that  receive  more  than  a  maintenance 
ration  and  use  the  excess  for  the  production  of  milk 
and  butter. 

Class  2.  Cows  that  receive  more  than  a  maintenance 
ration  and  use  the  excess  for  the  production  of  surplus 
flesh  and  fat,  storing  it  away  on  their  bodies,  growing 
heavier  every  day. 

Class  3.  Cows  that  receive  less  than  a  maintenance 
ration  and  have  to  draw  upon  the  food  nutrients  al- 
ready stored  on  their  bodies  in  order  to  keep  up  a  flow 
of  milk,  thus  growing  thinner  and  thinner  in  flesh  every 
day. 

This  third  or  last  named  class  is  seldom  found  in 
the  herd  of  the  man  who  feeds  silage.  He  feeds  as  a 
rule  an  abundance  of  palatable,  succulent  silage  in 
combination  with  other  feeds  richer  in  protein  content. 
The  protein  in  the  ration  goes  to  make  bone,  muscle 
and  the  curd  in  the  milk. 

Silage  is  a  roughage.  Rurrniants  require  a  greater 
per  cent  of  roughage  in  the  rat  m  than  do  other  classes 


Concrete  Silos  13 

of  animals.  Corn  silage  comes  the  nearest  to  having 
all  of  the  properties  of  good  green  grass  of  any  of  the 
feeds  we  have.  We  can  have  it  in  the  winter  time,  too, 
when  grass  is  gone  and  other  feeds  are  dry.  "We  can 
have  it  in  the  summer  time  when  the  grass  is  short  in 
dry  periods  of  drought.  Silage,  above  all  other  feeds, 
enables  the  dairyman  to  maintain  almost  unbroken 
summer  conditions,  conditions  under  which  the  maxi- 
mum amount  of  milk  and  butter  is  produced. 

A  feed  containing  a  large  amount  of  water  in  the 
form  of  natural  plant  juices  is  not  only  more  easily 
digested,  but  is  also  more  palatable  and,  besides,  serves 
the  useful  purpose  of  keeping  the  whole  system  of  the 
animal  in  good  condition.  A  silage-fed  animal  is  rarely 
troubled  with  constipation  or  other  digestive  disturb- 
ances, the  coat  is  noticeably  sleek  and  soft,  and  the 
skin  is  soft  and  pliable. 

No  rough  feed  is  more  palatable  than  good  corn 
silage.  Sometimes,  however,  a  cow  will  not  eat  silage 
readily  until  she  has  (acquired  a  taste  for  it;  this  may 
require  several  days.  But  silage  is  not  peculiar  in  this 
respect,  for  it  has  been  observed  that  range  horses  or 
cattle  shipped  into  the  corn  belt  refuse  corn  the  first 
time  it  is  offered  to  them.  The  quality  of  palatability 
is  of  great  importance,  as  it  induces  a  large  consump- 
tion and  stimulates  the  secretion  of  digestive  juices. 

The  advantage  of  silage  in  the  dairy  industry  was 
at  one  time  put  into  a  forcible  statement  by  W.  B. 
Barney,  state  dairy  commissioner  of  Iowa.  Among 
other  things  he  said: 

The  dairy  cow  is  the  most  economical  producer  of 
human  food  on  the  farm  if  fed  and  cared  for  in  an  in- 
telligent manner.  The  milk  of  a  cow  that  produces 
10,000  pounds  yearly  contains  8,710  pounds  of  water, 


14  Concrete  Silos 

290  pounds  of  fat,  485  pounds  of  sugar,  340  pounds 
of  protein  and  75  pounds  of  ash.  Therefore,  it  is  evi- 
dent that  the  cow  must  consume  large  quantities  of 
succulent  feed  to  produce  milk  economically.  The 
grass  in  summer  provides  her  with  such  feed,  but  if 
the  farmer  is  without  a  silo  his  cows  are  deprived  of 
succulent  feed  for  winter  use.  No  man  keeping  six  or 
more  cows  can  afford  to  be  without  a  silo,  regardless  of 
its  first  cost. 

Today  the  silo  is  no  longer  an  experiment,  and  prac- 
tically all  the  leading  dairymen  of  the  country  are 
using  them.  Some  seven  or  eight  thousand  new  silos 
have  been  built  in  Iowa  alone  during  the  past  year, 
which  is  sufficient  evidence  that  they  are  a  success. 
We  are  not  suffering  today  in  the  rural  districts  for 
the  want  of  finding  new  things  so  much  as  we  are  for 
the  simple  application  of  the  things  we  already  know. 
Practically  every  farmer  admits  that  the  silo  is  a  good 
thing,  but  he  puts  off  until  tomorrow  what  he  should 
do  today,  and  the  waste  of  crop  continues  from  year 
to  year.  In  the  corn  belt  where  stalks  are  allowed  to 
stand  in  the  field,  40  per  cent  of  the  crop  is  wasted. 
It  has  been  estimated  that  an  acre  of  corn  put  up  in  a 
silo  has  a  value  of  $45,  while  the  same  standing  in  the 
field  and  husked  has  a  value  of  $27.  Thus  it  can  be 
seen  that  the  silo  nearly  doubles  the  value  of  the  corn 
crop. 

In  feeding  silage  with  alfalfa  or  clover  hay  we 
have  practically  a  balanced  ration  all  raised  on  the 
farm.  Experiments  have  been  conducted  at  the  Kan- 
sas and  other  stations  which  show  that  the  grain  ra- 
tion can  be  cut  down  one-half  the  usual  amount  where 
alfalfa  or  clover  hay  and  silage  are  fed.  Silage  always 
plays  a  prominent  part  in  the  economical  ration  of  most 
farm  animals,  and  may  the  day  be  not  far  distant 
when  the  silo  will  be  as  common  a  sight  on  the  Iowa 
farm  as  the  corn  crib  is  today. 

In  the  Central  West  corn  is  hailed  as  the  king  of 
all  cereals,  forming  the  backbone  of  the  rations  of  the 
majority  of  our  farm  animals.  By  placing  corn  in  the 


Concrete  Silos  15 

silo  the  stalk  as  well  as  the  ear  is  preserved,  thus  mak- 
ing the  whole  corn  plant  available  for  feeding  pur- 
poses. Practically  40  per  cent  of  the  feeding  value  of 
the  corn  plant  lies  in  the  stalk,  leaves  and  husks,  the 
remainder  in  the  ear.  Therefore,  if  only  the  ears  are 
gathered,  much  of  the  remaining  40  per  cent  of  the 
crop  remains  in  the  field  to  bother  the  farmer  in  pre- 
paring his  seedbed  for  the  following  year.  As  corn 
should  be  cut  for  the  silo  before  the  lower  leaves  are 
lost  there  is  practically  no  waste.  About  twice  the 
amount  of  dry  matter  can  be  stored  in  the  form  of 
silage  as  corn  fodder.  A  cubic  foot  of  hay  in  the  mow 
contains  about  4.3  pounds  of  dry  matter,  while  a  cubic 
foot  of  silage  contains  8.9  pounds  of  dry  matter.  A 
cubic  foot  of  space  in  the  silo  is,  therefore,  worth  more 
than  twice  an  equal  space  in  the  mow. 

The  digestive  organs  of  animals  that  chew  their 
cud  are  so  formed  as  to  require  comparatively  juicy 
and  bulky  feeds.  The  cow  cannot  thrive  on  dry  feed 
as  well  as  the  horse.  The  ideal  food  for  the  dairy  cow 
is  green  pasture,  but  for  a  number  of  months  during 
the  year  she  is  deprived  of  this  feed.  The  best  sub- 
stitutions for  green  pasture  are  root  crops  and  corn 
silage.  As  silage  yields  twice  as  much  dry  matter  per 
acre  as  roots  and  does  not  require  as  much  labor,  silage 
is  by  far  the  more  economical  wherever  corn  can  be 
raised.  Silage  has  a  laxative  effect  upon  the  animal 
and  aids  in  maintaining  a  healthy  and  vigorous  condi- 
tion. 

The  population  of  the  United  States  is  doubling 
every  thirty  years,  which  means  that  the  farms  will 
gradually  become  smaller  and  that  more  feed  must  be 
produced  per  acre.  The  high  price  of  land  also  de- 
mands that  more  intensive  methods  must  be  used  to 
obtain  a  dividend  in  proportion  to  the  value  of  the  soil. 
Practice  tells  us  that  one  acre  of  corn  placed  in  the 
silo  will  yield  enough  feed  to  supply  a  milk  cow  40 
pounds  of  silage  for  500  days  or  4  cows  125  days. 

Another  important  factor  is  the  reduction  in  stor- 
age space  of  silage  compared  to  that  required  for  hay. 


16  Concrete  Silos 

One  ton  of  clover  hay  occupies  400  cubic  feet,  while  8 
tons  of  silage  can  be  placed  in  the  same  space.  The 
clover  hay  contains  886  pounds  of  digestible  nutrients, 
while  the  silage  contains  2,064  pounds.  Thus  the  corn 
silage  occupying  the  same  space  as  the  clover  hay  con- 
tains two  and  a  half  times  the  digestible  nutrients. 

Silage  as  a  milk  producer  compares  very  favorably 
with  the  other  more  concentrated  and  more  expensive 
feeds.  Being  a  very  succulent  and  palatable  feed,  it 
can  be  very  aptly  termed  the  great  substitute  for  pas- 
ture in  the  corn  belt.  We  all  look  forward  to  the  in- 
creased milk  flow  when  the  cows  iare  turned  to  pasture 
in  the  spring  after  having  received  nothing  but  dry 
feed,  for  six  months.  The  milk  cow  is  a  sensitive  ani- 
mal at  hard  work  and  should  be  nurtured  on  the  best 
feed  possible.  Silage  makes  possible  a  succulent  feed 
for  winter  use,  spurring  the  appetite  of  the  cow  and 
causing  her  to  relish  her  feed  in  winter  as  well  as 
summer. 

Several  years  ago  at  the  Ohio  Experiment  Station 
the  substitution  of  silage  for  grain  in  the  ration  proved 
very  successful.  Silage  was  used  to  take  the  place  of 
over  half  the  grain  ration  and  proved  to  be  much 
cheaper.  The  silage  ration  produced  milk  for  68  cents 
per  100  pounds  and  butter  fat  at  the  rate  of  13  cents  per 
pound.  The  grain  ration  produced  milk  at  $1.05  per 
100  pounds  and  butter  fat  for  22  cents  per  pound.  This 
made  the  profit  from  the  silage  ration  $5.86  per  month, 
and  of  the  grain  ration  $2.46  per  month. 

There  is  an  occasional  suggestion  that  milk  from 
silage  fed  cows  has  a  disagreeable  flavor.  In  order  to 
determine  what  foundation,  if  any,  there  was  for  this 
belief,  a  series  of  experiments  was  sometime  ago  un- 
dertaken by  the  Agricultural  Experimental  Station  of 
the  University  of  Illinois. 

For  the  purpose  of  these  experiments,  the  Univer- 
sity dairy  herd  was  divided  into  two  lots,  one  of  which 
was  fed  40  pounds  of  corn  silage  per  cow  per  day,  to- 


Concrete  Silos  17 

gether  with  a  small  amount  of  clover  hay  and  grain. 
The  feed  for  the  other  lot  consisted  entirely  of  clover 
hay  and  grain.  The  milk  from  both  the  lots  was  cared 
for  in  exactly  the  same  manner  and  was  standardized 
to  4  per  cent  of  butter  fat  in  order  that  there  might 
be  no  difference  in  the  flavor  of  the  two  lots  of  milk  on 
account  of  the  variation  in  this  respect. 

The  people  whose  tastes  were  consulted  with  re- 
gard to  the  milk  were  divided  into  three  classes :  ladies, 
men  of  the  faculty,  and  students. 

In  one  case  the  silage  had  been  fed  one  hour  before 
milking.  Of  the  29  ladies  who  sampled  this  milk,  10 
preferred  the  silage  milk,  14  the  non-silage,  and  5  had 
no  choice.  Of  the  men  of  the  faculty,  27  preferred  the 
silage  milk,  20  the  non-silage,  and  7  had  no  choice.  Of 
the  students,  20  preferred  the  silage  milk,  4  non-silage, 
and  4  had  no  choice. 

A  preference  for  silage  milk  was  indicated  by  51 
per  cent  of  the  111  tests  made  when  silage  was  fed 
one  hour  before  milking.  When  silage  was  fed  at  time 
of  milking,  71  per  cent  preferred  silage  milk,  and  when 
fed  after  milking  51  per  cent  reported  the  same  pref- 
erence. Of  the  total  tests,  amounting  to  372  persons, 
223  preferred  silage  milk,  109  non-silage  milk  and  40 
had  no  choice. 

In  making  an  investigation  of  the  entire  silo  ques- 
tion, The  Twentieth  Century  Farmer,  of  Omaha,  says 
that  it  found  one  man  who,  although  having  three  silos 
on  his  place,  claimed  that  silage  was  too  expensive  a 
feed  for  profitable  use,  and  that  he  would  not  recom- 
mend other  farmers  to  erect  silos.  He  told  the  investi- 
gator that  alfalfa  was  a  much  better  and  cheaper  feed 
and  he  believed  better  results  could  be  obtained  by 
feeding  more  alfalfa  and  less  silage.  He  was  discov- 


18  Concrete  Silos 

ered,  however,  plowing  up  an  alfalfa  patch,  putting  in 
some  corn,  and  not  feeding  any  new  alfalfa  that  season. 
This  resulted  in  an  investigation,  which  seemed  to  show 
that  the  man's  statements  were  prompted  by  selfish 
motives,  rather  than  by  his  real  feeling  in  the  oase.  It 
was  found  that  he  had  bought  up  during  the  winter, 
from  his  neighbors  who  did  not  have  silos,  and  were 
thus  compelled  to  sell,  a  lot  of  calves  and  young  cattle, 
feeding  them  on  the  silage  he  had  stored  in  his  silos 
and  making  a  very  nice  profit  on  the  deal.  If  his  neigh- 
bors were  encouraged  to  build  silos  the  possibility  of 
his  agiain  taking  advantage  of  their  unfortunate  cir- 
cumstance would  be  very  slight  indeed. 

One  line  of  investigation  followed  by  The  Twentieth 
Century  Farmer  was  to  find  out  whether  or  not  a  much 
larger  percentage  of  cattle  could  be  maintained  on  the 
farms  of  the  country  by  the  more  extended  use  of  the 
silo  and  the  feeding  of  silage  year  after  year.  This 
question  was  therefore  asked  of  numerous  farmers  of 
from  one  to  seven  or  eight  years'  experience  in  feeding 
silage,  what  percentage  more  of  cattle  could  be  kept 
profitably  on  their  farms  if  they  had  sufficient  silo  room 
in  which  they  could  be  sure  to  have  silage  to  supple- 
ment the  pastures  in  dry  periods,  and  also  to  have 
plenty  of  this  feed  for  winter  time.  While  none  of 
them  had  definite  figures  they  could  give,  they  all  had 
some  ideas  based  on  their  feeding  experience.  The 
answers  to  these  questions  from  probably  50  different 
silo  users  have  been  that  they  could  keep  from  50  to 
100  per  cent  more  cattle  by  the  use  of  the  silo  than 
they  could  without. 

Silage  stands  first  in  rank  of  all  the  roughages  for 
•finishing  cattle,  says  T.  E.  Woodward,  of  the  U.  S. 
Department  of  Agriculture.  Formerly,  during  the  era 


Concrete  Silos  19 

of  cheap  corn  and  other  concentrates,  little  attention 
was  given  to  the  roughage,  as  it  was  usually  considered 
merely  a  "filler"  and  of  very  little  economic  value  in 
feeding.  No  especial  care  was  taken  in  selecting  any 
particular  kind,  nor  was  the  quality  of  it  seriously  con- 
sidered. As  the  prices  of  the  concentrated  feedstuffs 
advanced,  the  feeder  looked  about  for  methods  of 
cheapening  the  cost  of  producing  beef,  and  soon  found 
this  could  be  accomplished  by  using  judgment  in  select- 
ing his  roughage  with  respect  to  the  grain  fed.  This 
has  continued  until  at  the  present  time  the  roughage 
receives  as  much  attention  as  the  concentrated  feed, 
and  has  been  made  to  take  the  place  of  a  large  amount 
of  the  latter.  The  feeding  of  silage  oame  into  general 
use  with  the  advent  of  expensive  grain  and  is  becoming 
more  popular  each  year.  With  the  present  prices  of 
feedstuffs,  there  is  hardly  a  ration  used  for  feeding  cat- 
tle which  cannot  be  cheapened  by  the  use  of  this  suc- 
culent feed.  By  combining  it  with  other  feeds,  the 
efficiency  of  the  ration  is  increased  to  such  an  extent 
that  the  amount  of  the  daily  gains  is  invariably 
greater  and  the  cost  of  producing  a  pound  of  gain  is 
lessened.  The  heaviest  daily  gains  are  usually  made 
during  the  first  stage  of  the  feeding  period,  and  silage 
can  then  be  used  to  advantage  in  large  quantities  with 
a  small  amount  of  grain,  but  as  the  feeding  progresses 
the  amount  of  silage  should  be  lessened  and  the  grain 
increased.  In  some  places  the  price  of  hay  and  stover 
is  so  high  that  the  greater  the  proportion  of  silage 
used  in  the  ration  the  more  profitable  is  the  feeding. 

Silage  is  a  quick  finishing  roughage  in  that  it  pro- 
duces large  daily  gains  and  produces  a  glossy  coat  and 
a  soft,  pliable  skin.  Moreover,  it  can  be  used  to  advan- 


20     •  Concrete  Silos 

tage  at  times  for  carrying  cattle  for  &  longer  time  so 
as  to  pass  over  a  period  of  depression  in  the  market,  or 
to  carry  the  cattle  along  in  thrifty  condition  so  they 
can  be  finished  at  a  later  period. 

For  many  years  the  belief  was  general  that  cattle 
which  received  silage  as  a  major  portion  of  the  rough- 
age would  have  to  be  kept  in  warm  barns  and  not  ex- 
posed to  the  cold.  While  they  do  need  protection  from 
the  cold  winds  'and  rains  and  need  a  dry  place  to  lie 
down,  it  has  been  clearly  demonstrated  that  warm 
barns  are  not  only  unnecessary,  but  that  fattened  cat- 
tle make  both  larger  and  cheaper  gains  when  fed  in 
the  open  sheds  than  when  confined  in  barns. 

Silage  can  be  profitably  used  to  supplement  the 
pastures  for  steers  during  a  time  of  drought,  when  they 
are  being  finished  for  market. 

The  general  impression  that  choice  or  prime  car- 
casses cannot  be  made  by  the  use  of  succulent  feed  is 
equally  untrue,  as  the  silage-fed  cattle  usually  make 
more  desirable  caroasses  than  cattle  fed  a  similar 
ration  except  that  silage  was  replaced  by  one  of  the 
coarse  fodders.  There  is  no  appreciable  difference  in 
the  percentage  of  marketable  meat  that  steers  will 
dress  out  which  have  been  finished  on  a  silage  ration 
and  »a  dry  ration.  The  meat  seems  equally  bright  and 
the  fat  as  well  intermixed  with  the  lean. 

A  number  of  the  agricultural  experiment  stations 
have  conducted  experiments  at  various  times  to  ascer- 
tain the  value  of  silage  as  a  rough  feed.  At  the  Mis- 
souri Station,  some  experiments  were  made  with  two- 
year-old  fattening  steers,  under  direction  of  Prof.  H. 
D.  Allison.  Without  going  into  the  details  of  this  ex- 
periment it  will  be  necessary  only  to  give  a  few  para- 


Concrete  Silos  21 

graphs  from  the  summary  made  by  Professor  Allison. 
He  says: 

A  ton  of  silage,  as  used  in  this  experiment,  was  ap- 
proximately equal  to  one-half  ton  of  clover  hay. 

Estimated  on  the  basis  of  net  profit  per  steer,  a  ton 
of  dry  matter  in  the  form  of  corn  silage  yielded  50.3 
per  cent  greater  value  than  a  ton  of  dry  matter  in  the 
form  of  shock  corn. 

It  is  evident  from  the  data  given  that  it  takes  less 
grain  in  the  form  of  shelled  corn  to  fatten  two-year-old 
steers  when  corn  silage  composes  a  part  of  the  ration. 

A  superior  finish  is  obtained  on  fattening  cattle 
which  are  marketed  in  the  spring  when  silage  composes 
a  part  of  the  ration. 

A  similar  experiment  at  the  Iowa  station  brought 
practically  the  same  results.  Regarding  it,  Prof.  John 
M.  Evvard  stated  that  "the  silage-fed  cattle,  without 
a  single  exception,  returned  greater  profit  than  when 
clover  was  fed  as  the  only  roughage.  By  using  silage 
the  gains  in  weight  were  cheapened  and  the  profit  per 
steer  increased." 

Some  very  valuable  cattle  feeding  tests  have  been 
conducted  at  the  Pennsylvania  State  Experiment  Sta- 
tion, among  them  an  experiment  to  determine  to  what 
extent  silage  could  profitably  be  used  in  steer  feeding. 
This  experiment  lasted  126  days.  The  results  of  the 
test  are  given  in  detail  by  Prof.  W.  A.  Cochel,  in  Bulle- 
tin No.  118,  issued  by  the  Pennsylvania  station. 

The  results  of  this  experiment  are  interesting  at 
this  point,  not  only  because  silage  formed  a  part  of  the 
ration  used,  but  on  account  of  some  valuable  data  de- 
rived, showing  that  during  the  early  part  of  the  feed- 
ing period  some  ear  corn  or  shelled  corn  can  profitably 
be  replaced  by  silage. 


22  Concrete  Silos 

In  his  Bulletin  Professor  Cochel  says:  "Experi- 
ments at  this  and  other  stations  have  shown  that  the 
addition  of  corn  silage  to  the  rations  that  are  usually 
fed  to  fattening  animals,  results  in  'cheaper  and  more 
rapid  gains  in  the  feed  lot,  and  that  its  succulent  nature 
causes  cattle  to  shed  the  hair  early  and  to  look  more 
attractive  than  those  fed  exclusively  on  dry  feeds.  A 
further  advantage  in  Pennsylvania  is  that  an  excellent 
quality  of  corn  silage  can  be  produced  in  localities 
where  the  season  is  too  short  for  corn  to  mature." 

The  value  of  corn  silage  as  a  part  of  the  ration  in 
fattening  cattle  is  also  shown  from  the  results  of  a 
feeding  test  conducted  at  the  Indiana  Experiment  Sta- 
tion. The  results  of  this  test  are  shown  by  Dean  J.  H. 
Skinner  and  Prof.  F.  G.  King,  in  their  Bulletin  No.  163. 
These  gentlemen  state  that: 

The  addition  of  corn  silage  to  a  ration  for  fattening 
cattle  decreased  the  consumption  of  shelled  corn  in 
amounts  closely  approximating  the  grain  content  of 
the  silage  consumed  by  the  cattle. 

The  addition  of  corn  silage  once  daily  to  a  ration 
of  shelled  corn,  cottonseed  meal  and  clover  hay,  re- 
duced the  cost  of  gains  $1.83  per  hundred  pounds  and 
increased  the  total  profits  $11.19  per  steer. 

The  substitution  of  corn  silage  for  clover  hay  in 
a  ration  of  shelled  corn,  cottonseed  meal  and  clover 
hay  reduced  the  cost  of  gain  $4.35  per  hundred  pounds 
and  increased  the  profits  $17.97  per  steer. 

The  more  nearly  corn  silage  replaced  the  clover  hay 
in  the  ration  the  cheaper  was  the  gain  and  the  greater 
the  profit. 

Corn  silage  produced  a  very  rapid  finish  on  the 
cattle. 

The  Missouri  Experiment  Station  has  secured  from 
a  large  number  of  farmers  in  that  state  their  experi- 
ence in  the  feeding  of  silage. 


Concrete  Silos  23 

In  reply  to  the  following  question:  "By  feeding 
silage  do  you  find  your  feed  bill  for  the  year  is  any 
less  than  when  silage  is  not  fed?"  196  correspondents 
out  of  200  answered,  "Yes;"  two  answered,  "I  don't 
know,"  and  two  said,  "  I  can't  tell  yet."  One  hundred 
and  fourteen  of  these  men  feed  cattle. 

Out  of  114  replies  to  the  following  question:  "Do 
you  find  that  it  requires  less  grain  to  fatten  a  steer 
when  silage  forms  a  part  of  the  ration?"  112  answered, 
"Yes;"  one  replied,  "I  do  not  know,"  .and  one  said, 
"I  have  not  had  enough  experience  to  enable  me  to 
answer  this  question." 

In  answer  to  the  question:  "Do  you  find  that  it 
costs  less  to  fatten  a  steer  when  silage  forms  a  part 
of  the  ration?"  112  answered,  "Yes,"  two  answered, 
"I  don't  know." 

The  correspondent  cattle  feeders  were  also  asked 
the  question:  "What  per  cent  has  the  feeding  of  silage 
lessened  the  cost  of  production  of  beef  on  your  farm  ? ' ' 
Out  of  79  replies,  there  was  but  one  who  was  willing  to 
say  that  there  was  no  decrease  in  cost ;  17  answered  25 
per  cent ;  10  answered  33  1-3  per  cent ;  12  answered  50 
per  cent;  while  other  replies  were  scattered  over  a 
wide  range  of  gain. 

A  stock  raiser  writing  to  The  Independent  Farmer 
has  this  to  say  of  the  feeding  of  silage : 

We  consider  the  silo  as  necessary  as  our  barns.  In 
fact,  we  could  not  afford  to  do  business  on  high-priced 
land  without  such  economical  feed  as  silage.  It  enables 
us  to  keep  up  a  heavy  milk  flow  from  our  cows  at  a 
very  low  cost.  During  the  past  year,  in  our  cow  test- 
ing association,  one  of  our  Holsteins  returned  us  a 
profit  of  $131  over  and  above  her  feed,  and  we  sold  our 
silage  to  her  at  $3  per  ton.  Our  entire  herd  returned 
us  an  average  profit  of  $101.05,  over  and  above  their 


24  Concrete  Silos 

feed.  This  does  not  include  the  calf,  manure,  nor  skim 
milk.  These  very  gratifying  results  to  us  would  have 
been  impossible  if  we  had  not  had  a  silo.  "We  use 
silage  a  great  deal  to  supplement  our  pasture.  In  fact, 
this  coming  summer  we  are  going  to  feed  silage  and 
alfalfa  the  year  around.  We  feed  silage  to  everything 
on  our  farm.  Brood  sows  especially  relish  a  light  feed 
each  day,  and  during  the  suckling  period  it  greatly 
stimulates  the  milk  flow.  Our  hens  are  considerably 
better  because  of  their  receiving  a  liberal  ration  of 
silage.  Our  brood  mares  and  colts  have  for  their  noon- 
day meal  during  the  winter  about  fifteen  pounds  of 
this  excellent  feed.  In  fact,  we  never  had  our  colts 
grow  better  than  since  we  started  feeding  silage  and 
alfalfa.  For  all  classes  of  live  stock  these  two  great 
feeds  go  hand  in  hand. 


CHAPTER  II 

WHAT  A  GOOD  SILO  SHOULD  BE 

Before  determining  whether  any  particular  type  of 
silo  is  good  or  bad,  it  is  necessary  first  to  decide  what 
are  the  requirements  which  make  for  efficiency  in  silo 
construction.  It  is  only  by  applying  certain  standards 
to  any  article  that  we  can  decide  on  its  fitness  or  un- 
fitness  for  the  purpose  for  which  it  was  intended.  It 
is  therefore  essential  that  everyone  who  has  to  do  with 
silos,  including  the  farmer,  the  builder,  the  agricul- 
tural engineer  and  economist,  and  the  promoter  of 
silo  construction,  should  know  how  to  value  a  silo  to 
determine  whether  it  will  do  the  work  expected  of  it 
and  justify  the  expenditure  of  money  which  it  requires. 

Let  us  then  set  down  the  principal  requirements 
for  an  efficient  silo.  It  should  be : 

1.  Airtight, 

2.  Moisture  proof, 

3.  Fire  proof, 

4.  Vermin  proof, 

5.  Frost  proof, 

6.  Strong, 

7.  Durable, 

8.  Cheap  as  to  maintenance  cost, 

9.  Round  in  shape, 

10.  Smooth  as  to  interior  walls. 

Having  thus  arbitrarily  stated   our  standards,   at 

least  most  of  which  will  be  recognized  as  correct  by 

anyone  who  understands  the  purpose  of  the  silo,  it  will 

nevertheless  be  worth  while  to  take  up  each  one  of 

(25) 


26  Concrete  Silos 

these   separately    and   determine   the    grounds    of   its 
importance. 

(1)  Airtightness.     It  is   quite  customary,   as  we 
have  already  done  in  the  first  chapter  of  this  volume, 
to  liken  a  silo  to  a  giant  fruit  jar.    And  whether  can- 
ning is  being  done  in  the  home  or  on  an  extensive  com- 
mercial soale  in  a  canning  factory,  it  is  recognized  as 
of  prime  importance  that  the  contents  of  the  can  shall 
be  sealed  positively  from  the  air.    For  this  purpose  a 
material  which  is  absolutely  airtight  is  used — glass  in 
one  instance,  and  tin  in  the  other — and  the  seal  is  made 
in  one  case  with  a  rubber  gasket  and  in  the  other  with 
a  solder  joint.     The  demand  for  the  exclusion  of  air 
has  a  perfectly  well  recognized  scientific  basis.     The 
spoiling  of  fruit  or  vegetables  in  a  can,  or  the  spoiling 
of  silage  in  a  silo  by  rotting,  is  simply  a  bacteriological 
action  and  will  not  take  place  unless  oxygen  be  pres- 
ent to  support  the  organisms  which  destroy  the  con- 
tents of  the  receptacle. 

(2)  Imperviousness  to  Moisture.     It  is  necessary 
that  the  walls  of  a  silo  be  impervious,  not  only  to  ex- 
clude moisture  from  the  outside,  which  at  times  might 
enter  in  such  quantities  as  to  do  considerable  damage 
to  the  contents,  but  also  to  preclude  the  possibility  of 
the  natural  juices  in  the  silage  from  being  lost.     As 
previously  pointed  out,  one  of  the  advantages  of  silage 
is  the  fact  that  these  juices  are  retained  rather  than 
being  allowed  to  evaporate,  as  in  the  case  of  ordinary 
hay.    So  the  silo  which  approaches  closest  to  the  ideal 
will  be  the  one  which  retains  the  contents  in  as  nearly 
its  original  condition  as  possible. 

(3)  Fireproof  ness.    In  addition  to  the  value  of  the 
silo   itself,   the   contents   of  the   silo   can  perhaps  be 
taken  at  a  value  of  about  $5.00  per  ton  as  an  average 


Concrete  Silos  27 

figure.  Assuming  that  one  has  a  silo  16  feet  in  diame- 
ter and  40  feet  high,  the  contents  of  this  silo  when  full 
will  weigh  about  180  tons  and  will  thus  be  worth  about 
$900.  The  situation  is  easily  imaginable,  however, 
where  the  value  of  the  contents  of  the  silo  could 
scarcely  be  estimated  in  dollars  and  cents — a  situation 
where,  if  it  were  to  be  destroyed,  the  feeding  value  of 
its  contents  could  be  replaced  only  through  much 
trouble  and  financial  distress.  Add  to  this  fact  that 
other  consideration  which  is  too  lightly  recognized, 
namely,  that  a  fire  on  a  farm  is  one  of  the  most  hope- 
less things  in  the  world,  placing  everything  in  its  wake 
practically  at  its  mercy  until  its  ravages  are  exhausted, 
and  it  is  easy  to  understand  why  fireproofness  is  placed 
as  one  of  the  essentials  of  the  ideal  silo.  A  report  of 
the  fire  marshal  of  Iowa  shows  that  480  barns  were 
destroyed  by  fire  in  that  state  in  a  single  year. 

(4)  Exclusion  of  Vermin.    Not  taking  into  consid- 
eration the  destruction  of  the  silage  which  may  be  ac- 
complished by  rats  and  other  pests,  it  is  necessary,  in 
order  to  maintain  the  qualities  enumerated  under  head- 
ings 1  and  2  above,  that  the  construction  of  a  silo  be 
such  as  to  exclude  these  animals.     The  silo  cannot  ex- 
clude air  and  moisture  if  it  is  of  such  a  construction 
that  rats  or  other  animals  can  make  holes  through 
which  they  can  run  in  and  out  freely. 

(5)  Exclusion  of  Frost.     This  is  a  consideration 
which  will  be  a  vital  one  in  some  latitudes,  while  in 
other  parts  of  the  country,  where  the  winters  are  less 
severe,  it  is  not  of  such  important  consideration.    It  is 
well  recognized,  of  course,  that  frozen  silage  should  not 
be  fed  to  animals.    The  type  of  construction,  therefore, 
which  can  completely  exclude  the  frost,  or  at  least  re- 


28  Concrete  Silos 

duce  the  amount  of  frozen  silage  to  the  minimum,  is  the 
efficient  type  to  build. 

(6)  Strength.    Experiments  have  shown,  as  noted 
in  another  chapter  of  this  book,  that  the  bursting  pres- 
sure on  a  silo  wall  is  11  pounds  per  square  foot  for  each 
foot  of  depth  of  silage;  that  is,  in  a  silo  built  to  a 
height  of  20  feet,  the  bursting  pressure  at  the  bottom 
of  the  silo  is  220  pounds  per  square  foot.    In  addition 
to  taking  care  of  this  inside  pressure,  the  silo  must 
also  be  sufficiently  strong  to  withstand  storms  of  vari- 
ous kinds.    Winds  of  high  velocity  and  much  force  are 
not  uncommon  and  tare  especially  prevalent  in  those 
parts   of  the   country   where   the   largest   number   of 
silos  is  likely  to  be  built;   and   as  climatic   disturb- 
ances of  this  kind  are  more  frequent  in  the  spring 
and  early  summer,  when  the  silo  is  likely  to  be  empty, 
it  is  quite  necessary  that  the  silo  itself  have  sufficient 
stability  to  meet  these  storms  without  any  dependence 
upon  the  contents  to  weight  it  down. 

(7)  Durability.    By  this  term  is  meant  the  ability 
of  the  silo  to  continue  in  service  without  -appreciable 
impairment  during 'a  long  term  of  years.    The  absolute 
cost  of  any  structure  is  not  the  initial  expenditure,  but 
the  cost  per  year  through  its  period  of  usefulness.    If 
for  instance,  a  silo  costing  $240  has  a  life  of  40  years, 
the  capital  investment  is  $6.00  per  year.    On  the  other 
hand,  if  a  silo  costing  $60'.00  has  a  life  of  but  4  years, 
the  capital  investment  is  $15  per  year. 

(8)  Maintenance.    This  is  a  question  which  must 
be  considered  in  close  connection  with  that  of  dura- 
bility.   The  structure  in  order  to  be  efficient  must  not 
only  entail  a  reasonable  capital  investment  per  year 
of  life,  but  must  also  be  as  free  as  possible  from  main- 
tenance cost.    A  silo  which  requires  considerable  time 


Concrete  Silos  .      29 

spent  upon  it  each  year  to  maintain  it  in  reasonably 
good  condition  is  not  as  close  to  the  ideal  as  we  should 
be  able  to  get.  For  one  thing  this  maintenance  is  an 
annoyance  and  an  expense,  and  for  another  thing  it  is 
likely  to  be  frequently  neglected,  thus  reducing  the 
preserving  power  of  the  silo. 

(9)  Shape.     The  cylindrical  silo  is  most  econom- 
ical of  material,  easiest  to  provide  with  resistance  to 
working  strains,  easiest  to  fill.    The  absence  of  corners 
makes  it  practically  impossible  for  air  pockets  to  form 
if  reasonable  care  is  exercised  in  filling. 

(10)  Smoothness  of  Interior  Walls.    By  having  the 
interior  walls  smooth  and  free  from  ledges  or  offsets, 
the  silage  will  settle  down  perfectly,  thus  effectually 
excluding  the  air  and  also  allowing  the  largest  pos- 
sible amount  of  silage  to  be  placed. 


CHAPTER  III 

How  CONCRETE  MEETS  THE  REQUIREMENTS 

Having  pointed  out  in  Chapter  II  the  standards  of 
efficiency  by  which  any  silo  must  be  judged,  it  is  of 
interest  to  note  how  completely  concrete  as  a  building 
material  fulfills  all  these  requirements. 

Concrete  can,  in  the  first  place,  be  made  both  air- 
tight and  moisture  proof.  It  is  well  known  that  the 
composition  of  concrete  can  be  governed  to  suit  the 
particular  requirements  in  any  case.  If  it  is  desired 
to  make  it  impervious  to  both  air  and  moisture,  it  is 
only  necessary  to  so  proportion  the  various  sizes  of 
aggregates  and  so  regulate  the  amount  of  cement  that 
dense  and  impervious  concrete  will  result. 

If  it  is  desirable  to  further  insure  the  non-porous 
nature  of  the  concrete,  it  may  have  added  to  it  some 
other  ingredient  for  making  it  still  more  dense.  There 
are  >a  large  number  of  such  products  on  the  market, 
perhaps  most  of  which  will  answer  very  well  the  pur- 
pose for  which  they  are  intended. 

The  same  result  can  also  be  attained  by  giving  the 
concrete  a  surface  treatment,  either  of  a  cement  wash 
or  of  some  proprietary  pore-filling  compound.  There 
are  also  a  number  of  these  on  the  market,  some  of 
which  have  a  bituminous  or  asphaltic  base  and  could 
be  used  only  on  the  interior  walls,  while  others  have  a 
pleasing  appearance,  or  are  absolutely  colorless,  and 
could  be  used  exteriorly. 

It  is  generally  conceded  that  concrete  itself  can, 
if  given  proper  attention,  be  made  sufficiently  dense 

(30) 


Concrete  Silos 


31 


for  all  practical  purposes;  but  with  the  addition  of 
one  or  the  other  of  these  methods  of  excluding  >air  and 
moisture,  there  can  be  no  doubt  whatever  of  the  effi- 
ciency of  concrete  for  silo  construction  so  far  as  these 
qualities  are  concerned. 

Concrete  has  proved  its  fireproof  qualities  on  so 
many  different  occasions,  and  in  so  many  different  situ- 
ations, that  it  is  scarcely  necessary  to  go  farther  than 
a  mere  statement  of  the  case.  There  are  on  record 


A  Silo  Which  Withstood  Fire  on  Farm  of  John  H.  McCoy, 
Harrisville,    Pa. 

instances  of  a  large  number  of  silos  which  have  suc- 
cessfully withstood  the  ravages  of  fire  where  all  other 
surrounding  buildings-  have  been  destroyed.  In  addi- 
tion to  saving  the  silo  itself,  concrete  is  such  a  poor 
conductor  of  heat  that  if  silo  openings  are  properly 
protected,  the  contents  of  the  silo  will  also  be  saved 
in  good  condition. 

Concrete  is  proof  against  the  .attacks  of  vermin. 
There  is  no  material  which  offers  stronger  resistance 
to  the  attacks  of  rats  and  other  pests  than  concrete. 

Concrete   will   give   as   good   a  protection   against 


32 


Concrete  Silos 


frosts  as  any  other  material.  Of  course  this  is  a  mat- 
ter which  varies  greatly  with  the  latitude,  so  that 
while  in  some  localities  frost  does  not  have  to  be  con- 
sidered, there  are  other  places  where  it  is  almost  im- 
possible to  exclude  frost  entirely.  In  these  latter  locali- 
ties it  has  been  found  that  a  double  concrete  wall  with 
an  air  space  intervening  will  reduce  the  destruction 
of  silage  by  frost  to  a  minimum.  In  fact,  it  is  safe  to 
say  that  there  is  no  latitude  where  corn  can  be  raised 
where  a  silo  of  this  kind,  if  properly  constructed,  and 
with  openings  protected,  will  not  keep  the  silage  in 
practically  perfect  condition. 


After  a  Cyclone  Near  Georgetown,   Kentucky,   in  Which   81   Barns 
Were  Destroyed  in  a  Single  County 


Concrete  Silos  33 

In  this  connection,  it  might  be  well  to  suggest  that 
frozen  silage,  which  is  often  attributed  to  frost  getting 
through  the  walls,  is  frequently  caused  by  insufficient 
protection  at  the  top.  The  fact  that  this  freezing  is 
only  around  the  wall  does  not  disprove  this  statement. 
The  silage  is  of  course  colder  next  to  the  wall  than  it 
is  in  the  middle  of  a  silo,  and  with  the  loss  of  heat 
from  above,  the  outside  ring  will  naturally  freeze  first. 
As  each  day's  silage  is  removed,  the  freezing  continues 
on  down,  and  the  farmer  believes  that  the  silage  is 
frozen  for  its  entire  depth.  Investigation,  however, 
would  in  many  cases  show  that  this  is  not  so,  but  that 
it  is  frozen  only  >a  few  inches  below  the  surface. 

As  to  strength,  concrete  is  also  subject  to  the  will 
of  the  builder.  By  the  addition  of  a  sufficient  amount 
of  steel,  he  can  build  it  to  withstand  any  desired 
strain. 

One  of  the  pre-eminent  qualities  of  concrete  is  dur- 
ability. When  once  built,  and  built  right,  it  is  prac- 
tically indestructible.  It  is  sufficiently  heavy  to  main- 
tain its  position  against  winds  or  other  elemental  forces, 
and  it  is  not  'affected  by  age,  except  that  as  it  grows 
older,  it  grows  stronger. 

The  objection  has  often  been  raised  against  cement 
that  it  is  affected  deleteriously  by  the  acids  in  the 
silage.  This  contention  has  never  been  proven  and 
there  are  numberless  authoritative  statements  to  the 
contrary.  It  might  be  pointed  out,  however,  that  even 
if  there,  should  be  a  slight  eating  away  of  the  con- 
crete by  these  acids,  such  action  can  effectually  be 
counteracted  -by  some  asphaltic  or  bituminous  prepara- 
tion once  every  three  or  four  years.  If  such  a  coat- 
ing as  this  is  considered  necessary,  this  is  practically 
the  only  item  of  maintenance  cost  which  it  will  be 


34  Concrete  Silos 

found  necessary  to  expend  upon  the  silo  other  than 
perhaps  occasional  renewing  of  the  roof,  unless  a  con- 
crete roof  should  be  put  on  in  the  first  place.  Concrete, 
therefore,  admirably  fulfills  the  requirements  of  low 
maintenance  cost. 

One  of  the  manufacturers  of  concrete  silos  has  gone 
to  considerable  trouble  to  gather  expressions  of  opin- 
ion from  the  various  agricultural  colleges  regarding 
the  concrete  silo.  An  expression  was  especially  asked 
on  the  question  of  the  effect  of  the  acid  in  silage  on 
concrete,  since  this  is  one  of  the  main  arguments  usixl 


Three  Concrete  Silos  in  Perfect  Condition  After  a  Wind  Storm 

• — Photo  by  Courtesy  of  Sanders  Pub.  Co.,  Chicago 

by  the   opponents  of  concrete  silos.     Some   of  these 
statements  are  as  follows : 

It  has  been  our  experience  on  the  college  farm,  and  the  experi- 
ence of  the  men  for  whom  we  have  supervised  the  construction 
of  the  cement  silos,  that  when  properly  built  they  preserve  silage 
in  first-class  shape.  We  have  never  noticed  the  effect  of  the  acid 
of  silage  on  the  walls  of  a  concrete  silo. — O.  E.  KEED,  Professor 
of  Dairy  Husbandry,  Kansas  State  Agricultural  College,  Man- 
hattan, Kansas. 

I  think  it  has  been  definitely  established  that  among  all  types 
of  silos,  the  concrete  silo  is  one  of  the  most  durable.  The  action 
of  the  acid  in  the  silage  on  the  durability  of  the  concrete  is  not 
a  large  factor  in  any  event,  and  when  the  silo  lining  is  covered 
with  a  proper  glazed  coating,  this  action  is  practically  negligible. 
— F.  B.  MUMFORD,  University  of  Missouri,  Columbia. 


Concrete  Silos  35 

0 

A  silo,  if  made  with  impervious  walls  so  as  to  exclude  the  air 
and  retain  the  moisture,  if  made  so  as  to  be  sufficiently  rigid  and 
of  sufficient  strength  to  resist  the  bursting  pressure  of  the  silage, 
and  lastly  if  smooth  on  the  inside  to  permit  the  silage  to  settle 
properly,  will  keep  the  silage  regardless  of  the  kind  of  material 
used  in  the  construction.  Concrete  silos  can  be  made  to  meet  all 
these  requirements.  There  is  abundant  evidence  of  this  and  in 
no  case  have  we  found  spoiled  silage  in  any  silo  where  these 
essentials  were  incorporated. — J.  B.  DAVIDSON,  Professor  of  Agri- 
cultural Engineering,  Iowa  State  College,  Ames. 

I  have  constructed  quite  a  number  of  concrete  silos  and  have 
found  that  when  the  concrete  silo  is  constructed  properly,  it  will 
preserve  the  silage  in  good  condition.  I  have  also  found  that  the 
acid  of  silage  has  very  little  effect  on  the  concrete. — J.  W.  RIDG- 
WAY,  Professor  of  Dairy  Husbandry,  Agricultural  and  Mechani- 
cal College  of  Texas,  College  Station. 

Concrete  silos  on  the  whole  will  keep  silage  as  well  as  any 
other  silo.  With  concrete  walls  made  of  properly  proportioned  and 
well  mixed  cement,  sand,  gravel,  and  the  inside  washed  with  grout, 
one  need  not  fear  injury  to  the  walls  due  to  the  acids  in  the  silage. 
I  have  examined  quite  a  number  of  concrete  silos  and  have  not 
seen  a  single  one  where  the  acids  have  made  any  permanent  injury 
to  the  walls.  It  is  my  opinion  that  the  effect  of  the  acids  in  silage 
on  a  concrete  wall  is  a  minor  matter. — C.  F.  CHASE,  Assistant 
Professor  Agricultural  Engineering,  North  Dakota  Agricultural 
College. 

It  is  my  opinion  that  concrete  silos  keep  silage  as  well  as 
other  makes,  and  that  when  the  concrete  of  the  silo  is  properly 
glazed  the  acid  in  the  ensilage  does  not  have  any  injurious  effect 
upon  the  concrete. — W.  L.  FOWLER,  Head  Department  of  Ani- 
mal Husbandry  and  Dairying,  University  of  Arkansas,  Fayette- 
ville. 

There  is  positively  no  truth  in  the  statement  that  cement  silos 
are  destroyed  by  the  acids  in  the  silage.  These  silos  have  been 
in  use  for  about  twenty  years.  A  few  days  ago  I  was  talking  to 
a  gentleman  who  had  just  examined  a  stone  silo  that  was  plas- 
tered with  cement  plaster  twenty-five  years  ago  and  had  not  been 
lepaired  since,  and  it  is  now  in  perfect  condition.  We  have  seven 
of  these  concrete  silos  on  the  college  farms  that  are  keeping  silage 
fully  as  well,  if  not  better,  than  our  two  wooden  silos. — A.  S. 
NEALE,  Dairy  Husbandry,  Kansas  State  Agricultural  College,  Man- 
hattan, Kansas. 

A  great  many  objections  are  made  to  concrete  as  a  suitable 
material  for  silo  construction.  These  statements,  of  course,  come 
from  competing  builders,  mostly  wood  stave  silo  people.  Obser- 
vations of  concrete  and  wood  stave  silos  standing  side  by  side  show 
that  the  freezing  is  not  greater  in  one  than  the  other.  By  coat- 
ing the  concrete  walls  with  a  wash  of  neat  cement  or  tar  pitch 
they  can  be  made  perfectly  air,  water  and  acid  proof.  That 
concrete  stave  silos  are  a  success  has  been  demonstrated  beyond 


36  Concrete  Silos 

a  doubt  by  those  built,  not  only  in  this  state,  but  other  states  as 
well.  Silos  of  this  type  are  known  to  have  been  used  successfully 
for  eleven  years  without  the  least  sign  of  deterioration  or  loss 
of  silage  through  spoilage. — AGRICULTURAL  EXPERIMENTAL  STA- 
TION, Ft.  Collins,  Colorado. 

Concrete  silos  have  been  in  use  for  at  least  fifteen  years  in 
this  state,  and  are  giving  excellent  satisfaction.  There  is  no 
serious  effect  of  the  silage  acid  on  the  concrete. — F.  M.  WHITE, 
Department  of  Agricultural  Engineering,  University  of  Wisconsin. 

Concrete  can  very  readily  be  made  round  in  shape. 
It  is  the  most  •  plastic  material  of  any  with  which  the 
silo  builder  will  have  to  deal,  and  can  be  fitted  perfectly 
to  his  requirements  in  every  way. 

Concrete  can  be  given  absolutely  smooth  interior 
walls.  In  monolithic  silos,  the  walls  will  automatically 
assume  a  smooth  surface  if  proper  care  is  used,  even 
without  any  surface  treatment,  while  where  concrete 
units  are  used,  these  form  an  admirable  surface  on 
which  to  plaster  or  to  apply  any  smooth  surface 
coating. 


CHAPTER  IV 

ADVANTAGE  OVER  OTHER  KINDS  OF  SILOS 

In  addition  to  concrete  there  are  five  materials 
which  are  sometimes  used  for  the  construction  of  silos 
— stone,  brick,  structural  tile,  wood  and  iron. 

In  every  one  of  these  concrete  is  'almost  invariably 
used  at  some  point:  for  the  foundation  wall,  the  floor, 
the  mortar  with  which  the  units  are  held  together,  the 
surface  finish,  or  the  roof.  This  being  the  case,  it  is 
coming  to  be  more  and  more  asked,  Why,  if  concrete 
is  a  good  material  for  these  parts  of  a  silo,  should  it 
not  be  used  for  the  entire  structure.  It  would  be 
worth  while  thus  to  do  away  with  the  complications 
arising  from  the  use  of  two  or  more  different  materials, 
if  for  no  other  reason. 

None  of  the  materials  enumerated  has  any  advan- 
tages over  concrete  as  a  material  for  silo  construction. 
Some  of  them  have  decided  disadvantages,  as  a  careful 
study  of  them  will  show. 

Of  all  the  above  materials,  stone  comes  perhaps 
nearest  to  having  the  high  percentage  of  efficiency  of 
concrete,  so  far  as  most  of  the  requirements  are  con- 
cerned ;  and  yet,  in  the  face  of  this,  it  is  the  one  mate- 
rial which  has  been  almost  abandoned  for  silo  con- 
struction. This  is  not  to  be  wondered  at  when  one 
comes  to  consider  the  matter;  for  it  is  a  slow  and 
expensive  construction,  giving  no  increased  benefit  for 
its  increased  cost.  There  are  comparatively  few  farms 
which  are  situated  advantageously  with  respect  to  a 
supply  of  stone  suitable  for  building  purposes;  while 

(37) 


38  Concrete  Silos 

if  such  a  supply  is  available,  it  is  a  slow  process,  and 
one  requiring  the  employment  of  expensive  skilled 
labor,  to  work  this  stone  into  shape  and  lay  it  up  in  the 
wall. 

Then,  too,  ordinary  building  stone  at  the  best  will 
usually  show  a  greater  degree  of  porosity  than  good 
concrete.  It  is  easy  to  see  why  this  is  so.  Concrete  is, 
to  be  sure,  composed  of  stone — possibly  even  a  poorer 
grade  of  stone  than  would  be  considered  fit  for  ma- 
sonry work;  but  in  concrete  each  particle  of  stone  is 
covered  with  a  film  of  cement,  while  in  stone  masonry 
there  is  no  such  protective  coating.  But  with  a  scarc- 
ity of  stone,  there  is  always  a  probability  that  one 
who  wants  to  build  with  this  material  will  be  satisfied 
with  Less  than  the  best,  thus  working  into  the  structure 
a  material  of  even  greater  porosity,  and  possibly  one 
also  which  will  disintegrate  rapidly  under  the  action 
of  the  elements.  Neither  will  stone  give  a  sufficiently 
smooth  interior  surface,  making  it  necessary  to  give  it 
a  plaster  coat  if  the  best  results  are  to  be  secured. 

Brick  is  open  to  the  same  objection  as  stone,  so  far 
as  porosity  is  concerned.  Tests  made  at  various  times 
and  places  have  established  beyond  question  the  fact 
that  a  well  made  concrete  has  a  greater  density,  and 
will  consequently  exclude  air  and  moisture  more  per- 
fectly, than  any  grade  of  brick  which  would  be  likely 
to  be  used  in  silo  building.  Brick  is  also  inexpedient 
for  this  purpose  because  of  the  fact  that  it  usually  has 
to  be  hauled  a  considerable  distance,  >and  on  top  of 
this  haulage  cost  is  often  a  freight  bill  for  shipment 
by  rail  from  a  distant  brick  yard.  In  the  case  of 
brick,  too,  practically  all  the  material  has  to  be  hauled 
in,  the  only  local  material  used  being  a  small  supply 


Concrete  Silos 


39 


of  sand  for  mortar,  if  such  is  obtainable,  though  the 
local  supply  might  be  of  such  a  quality  that,  while  very 
good  for  concrete  work,  the  bricklayer  would  not  con- 
sider it  of  the  right  quality  for  mortar. 

One  of  the  great  advantages  of  concrete  for  any 
work  on  the  farm  has  always  been  that  local  materials 
could  be  utilized  to  a  large  extent,  not  only  cutting 
down  the  hauling,  but,  where  a  good  grade  of  sand 
and  gravel  is  found  on  the  owner's  own  farm,  making 
the  cost  of  it  practically  nothing.  In  this  day  of  the 


Forty-Two  Acres  of  Corn  Spoiled  by  the  Collapse  of  This 
Clay  Tile   Silo 

study  of  economics  and  the  demand  for  efficiency  along 
all  lines,  it  would  indeed  be  a  sad  reversion  to  ineffi- 
cient methods  for  a  man  to  bring  in  outside  materials 
at  a  loss  not  only  of  hauling  time,  but  of  actual  cash, 
when  lie  has  suitable  materials  right  at  hand. 

It  is  a  difficult  matter  to  properly  reinforce  a  brick 
silo.    The  reinforcing  can  be  placed  only  in  the  mortar 


40 


Concrete  Silos 


joints  between  the  courses,  a  more  difficult  operation, 
and  giving  less  strength  than  where  the  rods  are  em- 
bedded in  the  concrete,  as  in  the  case  of  monolithic 
concrete  work,  or  where  they  have  special  grooves 
made  to  receive 
them,  as  in  the  case 
of  concrete  blocks, 
or,  again,  where  they 
completely  encircle 
the  silo,  as  in  con- 
crete stave  construc- 
tion. Bricks,  too, 
present  flat  surfaces 
to  each  other,  having 
no  bond  except  the 
mortar  joint  which 
connects  them,  while 
concrete  blocks  made 
especially  for  silo  work  usually  have  some  device  for 
interlocking  them  in  both  directions,  thus  making  them 
stronger  to  withstand  strains  either  from  within  or 
without.  And  brick  are  open  to  the  same  objection  as 
stone  in  that  they  do  not  present  a  smooth  interior 
surface. 

With  slight  modifications,  the  same  objections  that 
have  been  stated  against  brick  will  hold  good  as 
against  structural  tile.  The  air  space  of  the  structural 
tile  will  to  a  certain  extent  atone  for  its  porosity;  but 
on  the  other  hand  it  is  more  expensive  than  brick  and 
is  even  more  difficult  to  secure,  as  it  is  made  only  in 
widely  separated  plants. 

In  view  of  the  claim  of  the  opponents  of  concrete 
that  it  will  be  destroyed  by  the  action  of  the  acids  in 
silage,  it  is  interesting  to  note  the  illustration  here  re- 


This  Vitrified  Tile  Silo  Collapsed  First 

Night  After  Filling.     On  Farm  of 

Neff   Wildrick,    Colusa,    111. 


Concrete  Silos 


41 


produced  from  an  extensive  article  by  one  of  the  expo- 
nents of  clay  products.  He  calls  concrete  a  "good 
form  of  foundation  for  a  hollow  block  silo";  but  if  it 
is  good  enough  for  the  foundation,  where  the  juices 
gather  and  the  acids  are  the  strongest,  why  should  he 
consider  it  such  a  dangerous  material  for  the  body  of 
the  structure? 

There  are  perhaps  more  wood  silos  sold  than  any 
other  kind.  One  reason  for  this  is  that  they  are  cheap, 
and  another  is  that  they  are  short  lived  and  have  to  be 
replaced  frequently. 

Certain  qualities  that  are  inherent  in  the  very 
nature  of  the  material  of  which  wood  stave  silos  are 


A  Good   Form  of  Foundation  for  a   Hollow  Block  Silo. 


Illustration   Reproduced   from    "Brick   and   Clay   Record,"    Showing 
Concrete  Recommended  as  Foundation  and  Floor  For  a  Silo 

made  of  necessity  take  them  out  of  the  class  of  perma- 
nent structures  and  put  them  in  the  class  of  temporary 
expedients.  Wood  is  not  an  enduring  material,  espe- 
cially when  exposed  to  the  weather.  The  very  nature 


42  Concrete  Silos 

of  wood  is  such  that  it  shrinks  when  dry  and  swells 
when  wet.  The  permanency  of  a  wood  stave  silo 
depends  entirely  upon  its  maintaining  a  constant 
rigidity  of  structure.  It  consists  of  staves  set  on  end, 
held  firmly  in  place 
by  hoops.  As  long 
as  the  hoops  remain 
tight  the  structure 
will  be  comparative- 
ly rigid  and  stable. 
As  soon  as  the  hoops 
become  loose,  it  be- 
comes in  the  highest 
degree  unstable.  In 
the  modern  wood 
stave  silo  the  staves 
are  matched  and  fit- 
ted together  by 
tongue  and  groove. 
The  tongue  and 
groove  are  from  % 
to  %  inch  in  depth. 

The   extreme    Circum-       Effect    of    Shrinkage    of   Wood    Staves 

ference  of  a  silo  16  feet  in  diameter  is  about  50  feet.  It 
would  take  very  little  shrinking  to  reduce  this  50  feet 
sufficiently  to  separate  a  tongue  from  a  groove.  Then, 
unless  some  method  is  adopted  for  holding  the  stave 
in  place,  the  stave  will  fall  out  and  the  silo  be  in 
imminent  danger  of  collapse.  If  the  hoops  become 
loose  so  as  to  destroy  the  rigidity  of  the  structure,  it 
may  be  worked  in  any  direction  by  every  light  wind. 
A  single  half  day  of  hot  weather  is  sometimes 
sufficient  to  shrink  the  staves  on  such  a  silo  to  such 
an  extent  that  every  hoop  will  need  to  be  tightened 


Concrete  Silos 


43 


in  order  to  make  the  structure  safe.  When  the  hoops 
are  so  tightened,  a  single  shower  of  rain  will  swell 
them  to  such  an  extent  that  either  the  staves  will 
buckle  or  the  hoops  will  break.  Of  course,  there  can 
be  nothing  permanent  about  a  structure  made  of 
material  in  which  such  qualities  are  inherent.  An 
illustration  printed  herewith  is  made  from  a  photograph 
taken  on  the  inside  of  a  silo  and  shows  the  effect  pro- 
duced by  shrinking.  No  one  will  imagine  for  a  mo- 
ment that  such  a  silo  would  stand  erect  under  a  mild 
wind.  When  a  silo  collapses  it  is  a  matter  of  consider- 
able expense  to  erect  it  again.  No  farmer  will  be  satis- 
fied with  a  silo  that 
requires  such  con- 
stant attention  and  is 
in  such  constant  dan- 
ger. 

It  is  reported  by 
The  Twentieth  Cen- 
tury Farmer  that  a 
wood  stave  silo  was 
erected  on  the  state 
fair  grounds  at  Lin- 
coln, Neb.,  solely  for 
exhibition  purposes 
by  a  company  en- 
gaged in  promoting 
the  sale  of  just  such 
silos.  It  may  be 
taken  for  granted 
that  it  was  erected  in 
the  best  way  possible, 
in  strict  accordance 
with  the  mechanical  principles  involved  in  proper  erec 


Wood    Stave    Silo    Displaced    by    Wind 
— Photo   by  Courtesy  of  Virginia  Agr. 
Exp.    Station 


44  Concrete  Silos 

tion.  But  one  side  of  the  silo  was  blown  in,  thus  ren- 
dering it  praetic'ally  worthless  until  it  had  been 
repaired. 

During  the  summer  of  1911  thirty-one  stave  silos 
erected  in  the  vicinity  of  Lincoln,  Neb.,  were  inspected. 
In  the  inspection  no  silo  was  passed  by.  They  were 
taken  singly  one  by  one  as  they  were  found.  Here  is 
the  result  of  the  inspection: 

Five  had  blown  clear  down  once  before  they  had 
been  built  twelve  months;  one  blew  clear  down  twice 
before  it  had  been  built  twelve  months ;  one  blew  clear 
down  three  times  before  it  had  been  built  twelve 
months;  one  blew  clear  down  once  before  it  had  been 
built  five  years;  one  blew  clear  down  once  before  it 
had  been  built  nine  years;  two  blew  clear  down,  but 
the  date  of  their  erection  was  not  ascertained;  eight 
had  been  re-erected 
once  before  they 
were  up  twelve 
months ;  one  had  been 
re-erected  twice  be- 
fore it  was  up  twelve 
months ;  four  were 
leaning  badly ;  one 
had  been  straighten- 
ed twice;  two  had 

7  Wood  Stave  Silo  After  a  Fire 

very  loose  hoops ;  one 

had  broken  nearly  every  hoop  more  than  once;  only 

six  were  in  good  condition. 

With  such  a  record  as  this,  it  is  impossible  to  classify 
wood  stave  silos  as  permanent  structures,  and 
this  impossibility  rests  not,  as  the  wood  stave  silo 
men  claim,  upon  failure  to  observe  mechanical  prin- 
ciples in  the  erection  of  them ,  but  upon  qualities 


Concrete  Silos 


45 


inherent  in  the  very  nature  of  the  material  itself.  Nor 
can  such  a  state  of  affairs  be  charged  to  the  fact  that 
these  silos  were  not  properly  guyed,  because  no  guying 
is  sufficient  to  hold  such  material  in  place  with  a  proper 
degree  of  rigidity  to  insure  stability. 

No  wood  exposed  to  the  action  of  the  elements  is 
safe  from  decay.     The  rains  that  beat  upon  the  out- 
side of  a  silo,  the  change  in  moisture  conditions  and  in 
temperature,  the  ab- 
sorption of  moisture 
from     the     enclosed 
silage,    all    help    to 
hasten  the  process  of 
decay. 

The  Twentieth 
Century  Farmer  also 
states  that  it  has  on 
file  a  statement  from 
a  representative  of  a 
wood  silo  company 
to  the  effect  that  25 
per  cent  of  the  ensi- 
lage in  concrete  silos 
rots  beyond  use.  The 
editor  brands  this 
unhesitatingly  as  a 
false  statement.  This 
paper  has  made  an 
extensive  investiga- 
tion of  silos,  and  in 

the  course  of  this  investigation,  concrete  silo  after  con- 
crete silo  has  been  visited.  In  no  case  has  dissatisfac- 
tion with  such  a  silo  been  found  by  the  user.  Such 
silos  have  been  in  use  for  a  number  of  years.  The 


Failure 
E. 


of    Metal 
W.   Page, 


Silo    on    Farm 
Goltry,    Okla. 


of 


46  Concrete  Silos 

investigators  have  not  been  able  to  find  an  owner  of 
a  concrete  silo  who  would  build  a  silo  from  any  other 
material. 

Relative  to  the  action  of  acids  on  silos  the  publication 
above  quoted  says:  "It  is  very  glibly  stated  by  the 
salesmen  of  wood  stave  silos  that  the  acetic  acid  devel- 
oped by  the  process  of  fermentation  in  ensilage  corrodes 
and  e'ats  away  the  concrete  wall  so  as  ultimately  to 
destroy  it.  This  statement  at  first  glance  would  seem 
to  have  some  basis  of  truth,  for  the  reason  that  it  is  a 
well-known  fact  in  chemistry  that  acetic  acid  will  attack 
some  of  the  materials  of  concrete  wherever  found,  and 
thereby  produce  acetates.  This  fact  has  been  magnified 
and  has  been  used  by  wood  silo  men  to  damage  the 
reputation  of  concrete  silos.  But  here  is  another  fact: 
The  amount  of  acetic  acid  developed  in  fermenting 
ensilage  is  so  small  and  is  so  much  diluted  that  it  has 
practically  no  effect  whatever  upon  the  concrete.  Con- 
crete silo  after  silo  has  been  visited,  some  of  them 
having  been  in  use  for  more  than  25  years,  and  in  no 
case  has  the  least  evidence  of  the  action  of  acetic  acid 
upon  the  silo  wall  been  discovered.  The  walls  are  as 
smooth  and  clear  and  clean  after  25  years  of  service  as 
they  were  in  the  first  place. 

' '  The  greater  initial  cost  of  masonry  silos  is  another 
argument  used  against  them  by  the  wood  silo  men. 
This  argument  might  be  made  valid  if  the  wood  silo 
men  would  put  their  price  where  it  might  be  regarded 
as  reasonable.  This  fact,  however,  must  be  remem- 
bered— that  the  first  year's  loss  on  a  wood  silo  that 
blows  down  during  the  first  year  and  has  to  be  re- 
erected  amounts  to  more  than  the  initial  cost  of  any 
masonry  silo.  The  masonry  silo,  when  properly  re- 


Concrete  Silos  47 

inforced,  is  a  permanent  structure.  There  are  no  hoops 
to  tighten,  no  danger  from  blowing  down  or  from  fire. 
It  grows  stronger  and  more  stable  with  each  succeeding 
season.  It  is  good  for  generation  after  generation.  In 
some  places,  owing  to  cost  of  material,  the  initial  cost 
may  be  a  little  more  than  the  cost  of  a  wood  stave  silo, 
but  in  the  end  it  is  a  more  economic  structure. " 

With  reference  to  the  metal  silo,  it  will  scarcely  be 
necessary  to  do  more  than  quote  a  paragraph  from  the 
catalogue  of  one  of  the  companies  selling  these  silos. 
It  states: 

"In  the  production  of  silage,  certain  mild  acids  are 
formed  by  fermentation,  which,  if  no  protection  were 
afforded,  would  have  a  tendency  to  cause  the  galvan- 
izing to  corrode.  To  provide  against  this  it  is  advisable 
to  keep  the  inside  of  the  silo  painted  with  some  elastic, 
acid-resisting  paint." 

In  another  paragraph  the  company  advises  its  cus- 
tomers to  paint  the  inside  of  the  silo  once  a  year;  and 
this,  too,  is  a  company  which  is  selling  silos  of  "pure 
iron" — the  kind  which  is  supposed  to  be  proof  against 
attacks  of  any  kind. 

Granting  that  the  acid  in  silage  does  have  a  slight 
effect  upon  concrete,  such  a  wall,  with  a  thickness  of 
several  inches,  will  certainly  be  more  durable  than  a 
metal  wall  having  a  thickness  of  a  small  fraction  of  an 
inch. 

The  table  on  the  following  page,  which  is  a  com- 
pilation of  296  replies  to  inquiries  sent  out  to  Missouri 
farmers,  will  serve  to  show  the  difficulties  experienced 
with  silos  of  various  kinds  and  the  kind  of  silo  pre- 
ferred, if  another  should  be  built. 


48 


Concrete  Silos 


TABLE    I— RESULT    OP    INQUIRIES    MADE     AMONG     296 
MISSOURI  FARMERS 


K.rxd    of    Silo 

No 

rt^YYAWr- 

FVr  r.en» 
giv.rxg 

s 

.re  fe  r  r 

E     bVA.I  > 

n.%^ 

i  rv    use 

V  rouble 

made 

•=,  t  QV«  S    j       77 

3.-S. 

3S 

196 

£i  >c*ve 

;?.T? 

Blowing   down.15 

C.5 

Frozen    s.la^c,8 

3  5 

CracKed,     \ 

3. 

33 

CracHed  ,  2 

16  6G 

1  1 

Concrete  bUcK 

IJt 

Fraxe^s.Uge.l 

833 

Q^r»e^ 

e 

Fv  ocen  s>Uge,3 

33  33 

3 

c 

Home-made  sK««V 

mg*  4ar   paper 

rro»«»v  s.lage,    1 

1 

Rr 

From  this  table  it  will  be  seen  that  the  preference 
is  for  the  concrete  silo  if  another  kind  is  discarded.  Out 
of  one  hundred  men  having  some  difficulty  with  the 
stave  silo,  38  prefer  the  concrete  if  they  should  build 
another  silo.  Not  a  man  having  a  concrete  silo  ex- 
pressed a  desire  for  another  kind  in  the  event  that  he 
should  build  another. 


CHAPTER  V 

SIZE  AND  SHAPE  OF  A  SILO 

As  has  previously  been  stated,  economy  and  good 
construction  will  dictate  that  the  general  shape  of  the 
silo  be  cylindrical,  and  there  are  at  the  present  time 
practically  no  other  shapes  used. 

It  is  generally  understood,  too,  that  in  an  economic 
and  well  constructed  silo  certain  relations  must  be 
maintained  between  the  diameter  and  the  height.  It  is 
sometimes  stated  that  the  depth  of  the  silo  should  not 
be  less  than  twice  nor  more  than  three  times  the 
diameter.  This  rule  has,  of  course,  been  violated  in  both 
directions,  but  it  is  probably  a  less  serious  error  to  go 
above  this  rather  than  below.  In  fact,  higher  silos  are 
now  advocated  by  some  of  the  best  builders,  and  there 
is  a  tendency  in  some  sections  to  build  silos  higher  than 
formerly. 

It  is  of  course  recognized  that  the  greater  the  depth 
of  silage,  the  better  will  it  be  on  account  of  the  pressure 
from  above  forcing  out  the  air  and  helping  to  preserve 
it.  If  the  height  is  less  than  24  feet,  the  quality  of  the 
silage  will  not  be  of  the  best.  On  the  other  hand,  an 
excessive  height  will  increase  the  cost  of  filling  the  silo 
by  making  necessary  a  larger  amount  of  power  to  ele- 
vate the  material  into  it.  It  will  also  necessitate  a  long 
climb  for  the  person  whose  duty  it  is  to  get  the  silage 
out. 

Within  the  limits  defined,  it  is  an  easy  matter  to 
figure  out  the  size  of  silo  required  in  any  given  location. 
The  two  dimensions  will  in  general  be  fixed  by  two 

(49) 


50  Concrete  Silos 

different  considerations.  The  diameter  of  the  silo  will 
be  determined  by  the  size  and  nature  of  the  herd  to  be 
fed,  and  the  height  by  the  number  of  feeding  days  per 
year  for  which  it  is  desired  to  provide.  A  common 
error  in  building  a  silo  is  to  make  the  diameter  too 
great  for  the  size  of  the  herd.  When  once  a  farmer  has 
removed  the  top  layer  from  his  silage  and  has  com- 
menced to  feed  from  it,  the  silage  should  be  removed 
at  the  rate  of  not  less  than  2  inches  in  depth  per  day  in 
the  winter  time  and  3  inches  in  the  summer  time.  It 
is  necessary  to  establish  a  limit  of  this  kind  in  order  to 
insure  that  none  of  the  silage  shall  spoil. 

The  weight  of  a  cubic  foot  of  silage  varies  according 
to  the  pressure  to  which  it  is  subjected,  but  there  are 
certain  average  figures  which  can  be  taken  as  suffi- 
ciently accurate.  For  instance,  in  a  silo  30  feet  deep, 
a  cubic  foot  of  silage  will  average  about  40  pounds  in 
weight;  so  by  knowing  the  amount  of  silage  to  be  fed 
daily,  it  is  possible  to  estimate  what  the  diameter  of  the 
silo  should  be  to  permit  the  removal  of  a  certain  num- 
ber of  inches  in  depth  each  day. 

Table  II,  which  is  taken  from  Bulletin  No.  21  of  the 
Association  of  American  Portland  Cement  M'anufactur- 
ers,  shows  the  approximate  minimum  pounds  to  be  fed 
daily  from  the  various  diameters  of  silos.  This  is  based 
on  winter  feeding,  and  for  summer  feeding  would,  of 
course,  be  about  50  per  cent  more,  in  order  to  keep  the 
silage  in  good  condition.  This  table  also  shows  the 
number  of  animals  which  can  be  fed  from  each  silo  on 
the  amount  taken  'away  daily  at  a  stated  ration  for 
each  kind  of  animal.  Of  course,  many  feeders  will  not 
make  out  their  rations  according  to  this  table ;  but  with 
the  help  of  the  table,  and  substituting  their  own  weight 


Concrete  Silos 


51 


of  rations  for  the  ones  used  in  the  table,  they  can  de- 
termine very  accurately  what  size  herd  they  can  raise 
on  any  diameter  of  silo,  or  conversely,  they  can  deter- 
mine the  size  of  silo  necessary  for  any  given  herd. 
Multiplying  the  depth  taken  away  each  day  by  the 
number  of  days  which  they  desire  to  feed,  they  will  be 
able  to  get  the  height  of  silo  necessary.  The  usual 
figure  taken  is  180  days,  although  the  increasing  preva- 

TABLE    II— SHOWING    MINIMUM    NUMBER    OF    ANIMALS    TO 
BE   FED   DAILY  FROM  EACH   DIAMETER  OF   SILO 


fSu-mfcer   of  Animals  to  be  Fedt  from  ea.cK  Size 

D.oTne^r 

Approximate  /*lmi- 

of    Silo 

IT\ 

TTHAmPounnds-Vo 

Horses 

500-lb 

S  tocK 

Beef 

Dairy 

^Kee 

f~€  *  "V 

toe   Fed  Da.lv 

Calves 

C*^^"  ^"t* 

Covws 

*^ 

12   Ibs. 

2O  Ibs. 

2^  Ibs 

^O  Ibs. 

p^r"d!V 

1  O 

5*5 

44 

^6 

21 

13 

'75" 

1  2 

755 

63 

€3 

•3S 

30 

10 

S  5X 

I  4 

I03O 

94 

ee 

JX. 

•4  / 

26 

3-44 

16 

1  34Q 

12  X 

\  I  Z 

<S7 

54 

34 

•446 

18 

1700 

155 

1^2 

85 

GS 

•4JL 

^567 

20 

2  1  00 

19  1 

}-rs 

,0^ 

84 

S3 

loo 

lence  of  summer  feeding  is  another  factor  which  is 
helping  to  increase  the  height  of  silos. 

Table  III,  taken  from  BuUetin  141  of  the  Iowa  Agri- 
cultural Experiment  Station,  gives  the  capacity  in  tons 
of  various  diameters  and  heights  of  silos ;  also  the  num- 
ber of  acres  necessary  to  fill  the  silo  at  15  tons  per  acre, 
and  the  amount  which  should  be  fed  daily,  this  amount 
corresponding  to  that  given  in  the  second  column  of 
Table  II. 

The  Wyoming  Farm  Bulletin  suggests  that  the  fol- 
lowing formula  may  prove  serviceable  in  estimating 
the  actual  amount  of  silage  in  the  silo,  assuming  that  1 
cubic  foot  of  ensilage  weighs  30  pounds : 


52 

TABLE  III- 


Concrete  Silos 


-CAPACITY  OF  SILOS  AND  ACREAGE  NECESSARY 
TO  FILL 


1-rxSidQ. 

v-t  e'i  q  K  •* 

To-ns 

1  5    *o-»\  «  to  tKe. 
acme 

sXouJ  d   be  Fed 
daily    Pounds 

1  0 

aa 

4«. 

2.8 

5X5- 

lo 

30 

<4~T 

3.0 

S%.  S 

1  0 

3/2. 

SI 

3.4 

ff  Z>5 

I  O 

34 

5G 

3.  -7 

5  ~Z.  5" 

10 

3  Q 

es 

4.3 

d"  X  ^" 

IO 

•4  O 

TO 

>».6 

j-x<r 

IR 

X  8 

fet 

4.1 

7  5^- 

IA 

3  0 

G7 

4.  5" 

7  rf"^" 

i  jt. 

3  Jfc 

-74 

S-O 

7  SS" 

12 

3  4 

80 

^".3 

~rSS 

1  2. 

3  G 

S7 

5".  6 

-T6f 

1  3 

36 

94 

<2>.4 

~7  &S 

1  2 

4  O 

i  01 

7.3 

7  ^vr. 

I  4- 

2  a 

83 

j-.s 

1030 

1  4 

3  O 

91 

6.1 

10  3O 

1  4 

3  2. 

1  OO 

6.7            i 

IO3O 

1  4 

34 

109 

7.2 

1030 

1  4 

36 

l  Id 

7.  a 

IO3O 

I  4- 

38 

i  ae 

8.5- 

IO3O 

1  4 

<4-0 

138 

S>-2 

\O~3O 

16 

Z.8 

r  oe 

7.2 

I34O 

16 

3O 

1  19 

a.o 

/34(? 

16 

32 

13  1 

8.7 

/340 

16 

34 

1  43 

3.5" 

/34-C7 

16 

36 

1  ^"5" 

10.3 

/34O 

16 

3S 

1  67 

M.I 

/340 

IG 

-40 

/  SO 

12.0 

I34O 

1  8 

30 

I.SI 

10.0 

17  OO 

16 

3  2 

166 

II.  0 

iroo 

16 

34 

181 

u.o 

I7OO 

18 

3  6 

1  96 

13.2 

I70O 

IS 

3S 

^  1  /t 

14.1 

1700 

1  & 

•40 

223 

15.^6 

iroo 

IS 

4*2 

;?  46 

16.4- 

/~7OO 

I  & 

-4-4 

2  64 

/7.G 

I7QO 

IS 

4G 

262 

18.8 

1700 

2  O 

30 

I  87 

IX.  5 

2IOO 

51  O 

32 

20-5" 

13.6 

/2I  OO 

2O 

34 

•%.  ^.4 

I5".  0 

»l  OO 

36 

f^43 

16.2 

2100 

2O 

4o 

28  \ 

IQ.8 

2IOO 

X.O 

4;2 

300 

»o.o 

2'OO 

20 

44 

3X0 

21.3 

2'  O^ 

20 

46 

3^0 

22.6 

2/00 

2O 

4-S 

3GI 

24.0 

2IOO 

2.0 

.50 

3S^. 

2:£  5- 

»'  oo     QF 

Concrete  Silos  53 

D 

( — )2x3.14xHx30-— pounds  of  silage. 

2 
Where  D  equals  diameter  of  silo  in  feet. 

H  equals  depth  of  silage  in  feet. 

30  equals  weight  of  silage  per  cubic  ft. 

EXAMPLE:     To  get  the  capacity  of  a  silo  ten  feet  in  diameter 
containing  twenty  feet  of  silage. 

10 
(-)2X3.14X20X30= 

52x3.14x20x30= 

5X5X3-14X2°X30=47>100  pounds  silage. 
47,100-=-2,000=23.5  tons  of  silage. 

In  the  eighth  annual  report  of  the  Wisconsin  Agri- 
cultural Experiment  Station,  Prof.  F.  H.  King  gives 
the  results  of  investigations  to  determine  the  pressure 
of  silage  against  the  silo  wall.  It  was  found  in  these 
experiments  that  the  pressure  of  silage  upon  the  silo 
walls  increases  with  the  depth  and  is  equal  to  11 
pounds  per  square  foot  of  each  foot  of  depth.  Thus  at 
a  depth  of  20  feet,  the  bursting  pressure  in  a  silo  is 
220  pounds  per  square  foot,  and  at  a  depth  of  35  feet 
the  pressure  amounts  to  385  pounds. 

Prof.  J.  B.  Davidson,  of  the  Iowa  Experiment  Sta- 
tion, Ames,  la.,  says  that  a  careful  investigation  of 
modern  practice  proves  that  an  allowance  for  this  pres- 
sure is  sufficient,  and  that  many  concrete  silos  are  now 
standing  and  in  successful  service  with  much  less  re- 
inforcement than  that  required  by  an  assumed  pressure 
of  11  pounds  per  square  foot  per  foot  of  depth.  This  is 
due  to  the  fact  that  the  wall  independent  of  the  steel 
is  able  to  resist  a  part  of  the  bursting  pressure. 

Table  IV,  prepared  by  Prof.  Davidson,  gives  the 
steel  required  in  cylindrical  silos  to  carry  a  bursting 
pressure  of  11  pounds  per  square  foot  per  foot  of  depth 
and  it  is  based  on  a  safe  tensile  strength  of  20,000 


TABLE    IV— TO    DETERMINE    STEEL    REQUIRED    IN 
REINFORCING   SILOS 


GrQSs-^ectiona^Areq  of^Ste 

el    S           JQi      |    8|          «! 

Nurinberlof  2!  incHi  Squar£  B 

!          j-|     !           :       ^          : 

drs 

;  «o|              .rj              «oi 

NurjibeHof  ij  inert  Round  R< 

!     -I       j     *M|;         i    fO|: 

>(?5 
••  •*!           mi  i          o|            si 

Nur^beij  of  Ij  inolH  Rdonc)  R< 

;  .     :      "        i-i     i       s 

3fi 

rvj|                                                 tO| 

Nurjnberj  of  2  inoHi  Rcjunc)  R< 

Dds 

i    -                     1                    1                    1 

Nurpbe*  of  |  inch  Rqundj  R 

ods 

1               -1 

Nurpbei-of  jinch  Round  R 

!           j                 -Wl                    : 

otls 

-Ml                              rttai 

Sfrjandis  of^NcJ-Q  VVirei   c 

Ji!    .    ,        i  GI        i    .      ^ 

,  Strands  of  BdrbWirei-2 

0                                         !«0         i,            !      ,            < 

,-No.liS  Wrres...                    0 
h     ,     i    i    .  vi         .           ^ 

5-  -  I     - 

ii 

i    j  £  ^ 

\>\  V  ^ 

10                  s  J  j  i 

S      kS^^' 

C  ^             L  ^ 

i       i         S 

!  [!  5  !  i  I  !! 

i                   S             S 

S   ^  *    ^  s 

i    k  5  5   k      *  t.  s 

^_.  20    •            ..L.(.^  .^  »   1.^1.,.. 

^                      ..    ..,.  ,  .,          .^.     .. 

a)                      ;s      5!S"  i  >'! 

iJ_       ::  !i:!:^:r!;!s':: 

COC     .        .   .    L  .  '   .   .   k                  S          S 

==                                 »       k                \    \           S 

*         k       C             ^  '  '  1 

o      :::::::::::::!  ::s:.i:.5]!;:!;:!; 

in  -^n                        \    ,  v  ^ 

u     OO                                    i                 >     S 

^         ^            i  3  - 

o                            i         ;"^"s; 

S         *  ^  |  >  ^  ,  • 

...                             ..      s 

S            I 

V           i  "     S          s  rf^* 

^1   35                                                  "  "      '  '  T  -  -  -  r  -  -  -  r  -  - 

'-l^          S     x    S'?1 

CP     :::  :  ::::  :::s:  •;••  ss 

•-)                 :  .  j  *    . 

.   ' 

•r      -  —  'ti  -\  ••• 

^40  Hs:l  ::.s:; 

•  i  '  -  •  ^  •  •  "^:  *   M  —  s&J^--~ 

^   *              ^                  '      j 

45                                  •••  c  —  j-s- 

S        S        I   i  ]  !  J  !  ,  .5^  .  .  -^  .  .  -  

^                                                                 .                    V                    ^ 

"         ^               ^                                    L               ^                  ^ 

.  .  j.  ...^ 

'                  s       '         ^ 

Q            8             2             fi. 

^         S3.         8         8 

Gross-sectional  Area  of  Sieel  per  Vertical  foot  of 
WallinHundredths  of  a  Square  inch 

(54) 


Concrete  Silos  55 

pounds  per  square  inch  for  the  steel.  This  shows  in  a 
concise  form  the  cross-sectional  area  of  steel  required 
in  silos  from  10  to  25  feet  in  diameter  for  the  top  foot 
and  each  successive  foot  until  a  depth  of  50  feet  is 
reached.  The  chart  should  be  held  in  a  vertical  posi- 
tion. Then,  if  the  point  is  noted  where  one  of  the 
heavy  diagonal  lines  representing  a  silo  diameter  inter- 
sects a  horizontal  line  representing  the  depth  of  the 
silo,  the  area  of  the  steel  required  to  resist  the  bursting 
pressure  on  a  section  of  the  silo  wall  one  foot  wide 
will  be  found  on  the  scale  directly  below.  The  corre- 
sponding area  in  common  styles  of  reinforcement  is 
found  directly  above  on  the  upper  scales. 


CHAPTER  VI 

THE  DIFFERENT  TYPES  OF  CONCRETE  SILOS 

Concrete  silos  naturally  divide  themselves  into  two 
broadly  general  classes :  Those  which  are  built  up  in 
position  and  which  form  when  completed  one  practic- 
ally continuous  monolithic  mass;  and  secondly,  those 
which  are  built  up  from  structural  units  of  concrete 
previously  manufactured. 

This  is  a  classification  somewhat  different  from  that 
used  by  other  writers  on  this  subject,  but  it  is  believed 
that  careful  consideration  will  show  it  to  be  logically 
correct. 

The  metal  lath  silo,  for  instance,  has  usually  been 
considered  in  a  class  by  itself,  and  apart  from  the 
monolithic  silo.  In  any  broad  general  classification, 
however,  it  would  seem  to  belong  with  the  monolithic 
silo  inasmuch  as  it  is  built  up  in  place  and  forms  prac- 
tically one  solid  mass  when  completed,  the  main  differ- 
ence being  that  it  is  plastered  in  vertical  layers  instead 
of  being  poured  in  horizontal  sections.  The  pit  silo,  if 
it  is  considered  at  all,  will  also  come  under  this  classifi- 
cation, it  being  a  plastered  silo  underground  instead 
of  above  ground. 

This  first  classification  will  also  include  the  hollow 
wall  silo  when  poured  in  place. 

The  second  classification  will  include  the  silo  built 
of  concrete  blocks,  concrete  staves,  or  any  other  form 
of  structural  units  which  are  made  previous  to  the  erec- 
tion of  the  silo. 

(56) 


Concrete  Silos  57 

The  determination  of  the  particular  type  of  silo  to 
be  erected  in  a  given  place  will  depend  upon  a  number 
of  considerations.  While  there  may  be  several  things 
which  in  any  given  locality  will  point  to  one  type  of 
silo  as  somewhat  more  suited  to  the  conditions  than 
another,  the  principal  consideration  governing  the 
choice  will  in  most  cases  be  found  to  be  the  whim  of 
the  owner.  It  is  unfortunate  that  this  is  so,  but  it  is 
one  of  the  conditions  to  be  reckoned  with.  Aside  from 
this,  however,  there  are  logical  conditions  which  will 
influence,  or  should  influence,  the  choke  of  type.  Two 
extreme  cases  might  be  cited  as  illustrating  this. 

Suppose,  for  instance,  that  there  is  a  good  deposit  of 
sand  and  gravel  on  a  man's  farm,  and  that  there  is  a 
contractor  in  a  nearby  village  who  has  a  set  of  forms 
for  building  monolithic  silos,  and  with  a  reputation  for 
building  them  well;  these  conditions  would  naturally 
point  toward  the  monolithic  silo  for  this  particular  loca- 
tion. On  the  other  hand,  suppose  another  farmer,  who 
has  no  available  deposit  of  sand  and  gravel,  but  who  is 
within  convenient  hauling  distance  over  good  roads 
from  a  plant  where  he  can  procure  structural  units  of 
some  kind  for  silo  construction.  These  conditions  will 
as  certainly  point  to  the  use  of  such  units. 

There  will,  of  course,  be  many  modifications  of 
these  conditions,  at  some  time  some  of  them  possibly 
pointing  in  one  direction  and  some  in  the  other.  They 
will  then  have  to  be  weighed  against  each  other  and 
the  decision  made  in  the  direction  of  those  which  seem 
to  be  most  favorable. 

The  labor  situation  may  influence  the  selection 
somewhat.  If  stone  masons  are  available  and  plasterers 
are  not  to  be  had,  this  would  tend  to  make  one  favor 


58  Concrete  Silos 

the  silo  of  structural  units  as  opposed  to  the  metal 
lath  silo;  while  with  reverse  conditions,  the  opposite 
would  be  the  case.  A  strike  in  one  of  these  trades 
would,  of  course,  throw  that  particular  mode  of  con- 
struction out  of  consideration  for  the  time  being. 

The  fact  that  a  neighbor  has  a  silo  of  a  certain  type 
of  construction  will  often  influence  a  man  to  have  the 
same  type.  This  method  of  selection  is  logical  only  to 
the  extent  that  it  shows  there  is  someone  in  the  locality 
who  can  build  successful  silos  of  that  type  and  gives  the 
new  builder  greater  confidence  that  his  silo  will  be 
what  it  should  be.  His  situation  as  to  materials  or 
labor,  however,  may  be  entirely  different,  so  that  this 
in  itself  is  not  sufficient  basis  for  choice. 

There  may  even  be  times  when  one  will  not  be  justi- 
fied in  going  to  greater  expense  than  that  involved  in 
the  construction  of  a  pit  silo.  In  doing  this,  however, 
he  must  be  sure  that  his  conditions  are  right  for  this 
type  of  silo,  and  outlined  in  another  chapter  of  this 
book. 


CHAPTER  VH 

THE  FOUNDATION  OF  THE  SILO 

The  silo  is  usually  allowed  to  extend  into  the  ground 
about  5  feet.  In  this  way  the  height  above  ground  is 
reduced,  considerably  decreasing  the  amount  of  scaf- 
folding necessary,  and  the  hoisting  of  materials,  as  well 
as  having  the  further  advantage  of  placing  the  founda- 
tion below  the  frost  line. 

It  might  at  first  seem  that  if  a  depth  of  5  feet  is  an 
advantage,  a  greater  depth  would  be  a  still  further  ad- 
vantage; but  this  is  not  true,  owing  to  the  fact  that 
when  one  goes  below  5  feet,  the  difficulty  of  getting  the 
silage  out  of  the  silo  offsets  any  advantages  of  con- 
struction which  might  be  secured. 

When  the  site  of  the  silo  has  been  selected,  a  stake 
is  driven  in  the  center  and  a  sweep  is  attached  to  this 
stake  with  a  spike,  by  which  the  place  for  excavation 
can  be  marked  out.  This  sweep  may  consist  of  a  piece 
of  2x4,  or  any  other  convenient  piece  of  lumber,  to  the 
outer  end  of  which  is  attached  a  pointed  piece  of  board, 
by  which  the  marking  can  be  done.  The  length  of  the 
sweep  will  of  course  be  governed  by  the  diameter  of  the 
proposed  silo,  as  well  as  the  nature  of  the  ground  in 
which  the  excavation  is  to  be  made.  First  measure  off 
on  the  sweep  from  the  spike  in  the  center  stake,  one- 
half  the  inside  diameter  of  the  proposed  silo.  If  the 
ground  is  firm,  so  that  the  walls  will  stand  vertical,  1 
foot  can  be  added  to  this  radius.  If,  however,  the 
ground  is  soft  and  yielding,  so  that  it  will  be  necessary 
to  slope  it  back,  it  will  be  necessary  to  add  about 
feet. 

(59) 


60  Concrete  Silos 

If  a  floor  is  to  be  put  in,  the  excavation  should  be 
carried  down  to  4  inches  below  the  top  level  of  the 
floor,  making  a  4-inch  slab. 

Under  certain  conditions,  the  silo  floor  may  -be  dis- 
pensed with  without  interfering  with  the  preservation 
of  the  silage.  Where  the  silo  rests  upon  dry  clay  or 
any  non-porous  soil,  and  where  the  foundation  is  deep 
enough  to  prevent  undermining  by  rats,  the  floor  may 
be  omitted.  In  general,  however,  a  floor  is  quite  de- 
sirable. The  portion  of  the  silo  below  the  ground  may 
be  made  more  nearly  water  tight,  the  floor  may  be  thor- 


Sweep  for  Laying  Out  Excavation. 

oughly  cleaned,  and  there  is  no  mixing  of  earth  with 
the  silage.  A  silo  floor  need  not  be  thick  or  expensive, 
as  the  weight  of  the  silage,  though  very  great,  is  dis- 
tributed evenly  over  the  surface  and  would  be  just  as 
firmly  supported  if  the  floor  was  not  used. 

After  the  excavation  is  leveled  off  for  the  floor  of 
the  silo,  the  digging  is  then  continued  around  the  cir- 
cumference of  the  pit  for  an  additional  depth  of  8 
inches,  and  24  inches  in  width,  to  provide  for  the  foot- 
ings, as  shown  in  the  drawing.  It  is  a  good  plan  to 
provide  in  the  center  of  the  silo  floor  a  connection  with 


Concrete  Silos 


61 


Excavation,    Floor   and   Footing1.      Earth   Wall   Can   Be   Made 
Vertical   Where   Ground   Is    Firm. 

a  line  of  drain  tile.  This  drain  will  carry  off  any  water 
which  may  accumulate  in  the  silo,  and  which,  in  some 
cases,  has  been  known  to  rise  to  such  a  height  as  to 
exert  a  pressure  on  the  silo  walls  greater  than  they 
were  designed  to  resist.  If  a  drain  is  used,  the  floor  of 
the  silo  should  have  a  pitch  toward  the  center  of  about 
i/4  inch  to  1  foot.  The  drain  should  also  be  covered 
with  wire  netting  to  keep  it  open,  and  should  be  pro- 
vided with  some  form  of  trap  so  that  the  air  cannot 
enter  from  the  outside. 

If  the  foundation  walls  on  the  silo  are  made  thicker 
than  the  walls  of  the  superstructure,  they  should  line 
up  with  each  other  on  the  inside  rather  than  the  out- 
side. A  few  years  ago  it  was  thought  proper  to  place 


Correct   Method    of   Alignment   Between   Wall   and    Foundation 
Shown  at  A.     Incorrect  Method   at  B. 


62  Concrete  Silos 

the  upper  part  of  the  silo  at  the  outer  edge  of  the  foun- 
dation walls.  The  shoulder  was  thus  left  projecting 
into  the  silo.  Owners  of  such  silos  report  a  large 
amount  of  rotten  silage  around  the  joints.  This  is  ow- 
ing to  the  fact  that  the  silage  does  not  settle  properly 
where  such  joints  occur,  leaving  pockets  of  air  which 
cause  rotting  of  the  silage.  In  some  cases  the  owners 
have  felt  it  worth  while  to  sacrifice  a  part  of  the  ca- 
pacity of  their  silos  by  filling  them  up  to  this  shoulder. 

If  the  ground  is  firm  it  can  foe  used  as  an  outside 
form  for  the  foundation  walls,  using  an  inside  form  of 
wood  or  metal. 

It  may  be  said,  however,  that  while  it  has  been  the 
custom  in  the  past  to  build  a  foundation  wall  up  to 
about  a  foot  above  ground,  irrespective  of  the  kind  of 
construction  to  be  followed  above  that  point,  the  prac- 
tice is  coming  into  quite  general  use  of  starting  the 
walls  of  the  structure  directly  on  the  footing,  making 
them  uniform  from  that  point  to  the  top,  whether  they 
be  of  monolithic  construction,  blocks,  staves,  or  plas- 
tered on  metal  lath.  This  is  a  more  simple  method  of 
construction,  except  for  the  fact  that  in  some  instances 
this  may  require  a  little  more  excavation. 

Where  a  silo  is  to  be  reinforced  vertically,  this  re- 
inforcement should  be  imbedded  in  the  footings  and 
allowed  to  project  from  them  up  into  the  walls. 


CHAPTER  VIII. 
THE  MONOLITHIC  SILO. 

The  word  "monolith"  is  derived  from  two  Greek 
words  and  means,  literally,  a  single  stone.  The  term 
"monolithic"  is  therefore  applied  to  concrete  struc- 
tures which  are  built  up  in  one  continuous  process  and 
form  practically  a  single  stone  when  they  are 
completed. 

As  stated  in  a  previous  chapter,  any  broadly  general 
classification  of  silos  would  include  under  this  heading 
not  only  the  silo  which  is  built  up  of  either  solid  or 
hollow  walls  poured  in  forms,  but  also  the  pit  silo  and 
the  silo  plastered  on  metal  lath.  These  others  are, 
however,  dealt  with  in  separate  chapters  further  on  in 
this  volume ;  and  as  a  number  of  different  systems  have 
been  developed  for  constructing  the  silo  of  poured 
walls,  these  too  have  been  dealt  with  in  other  chapters, 
so  that  this  chapter  need  only  concern  itself  with  a  few 
general  observations  on  this  type  of  silo. 

It  has  been  the  custom  in  the  compilation  of 
bulletins  by  the  U.  S.  Department  of  Agriculture,  the 
experiment  stations  of  the  several  states,  and  the 
bulletins  of  the  cement  companies,  to  give  detailed 
directions  for  what  'are  known  as  "home-made"  silos; 
that  is,  silos  built  wholly  or  largely  by  the  farmer  him- 
self, and  in  forms  which  are  also  of  his  own  manu- 
facture. The  present  writer,  after  having  given  the 
subject  careful  consideration,  has  not  seen  fit  to  include 
such  matter  in  this  volume.  While  undoubtedly  a  large 
number  of  very  satisfactory  silos  have  been  built  in  this 
way,  the  practice  is  not  to  be  recommended.  The 

(63) 


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r^  ~ 

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fes 


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7  "5   «C    k)  «o    10 


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GOTO     CP    «<    09    (J)    c<    00 


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oo 


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cv;    O    O 


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o  10 


O    —'    T 
N    (V    (V 


(64) 


Concrete  Silos  65 

writer  firmly  believes  that  every  silo  should  be  erected 
by  'a  contractor  who  is  familiar  with  this  class  of  work. 
There  have  been  failures  of  concrete  silos  in  the  past 
and  the  opponents  of  this  form  of  construction  have  not 
hesitated  to  use  these  instances  to  the  best  advantage 
in  inviting  public  condemnation  of  concrete. 

It  is  absolutely  necessary  for  the  benefit  of  the 
industry  that  no  more  such  failures  should  occur;  and 
one  of  the  best  expedients  for  preventing  their  recur- 
rence is  to  allow  only  an  honest  and  experienced  con- 
tractor to  put  up  a  concrete  silo.  Such  a  contractor 
will  scarcely  care  to  bother  with  making  his  own  forms, 
which  at  best  will  be  awkward  and  inefficient, 
especially  in  view  of  the  fact  that  there  are  on  the 
market  a  constantly  increasing  numbjer  of  commercial 
forms,  and  that  the  manufacturers  of  these  forms  are 
continually  improving  them  and  adding  to  their 
efficiency  for  construction. 

A  home-made  form  will  perhaps  build  a  dozen  silos 
at  best,  when  it  has  to  be  discarded  and  replaced.  It  is 
a  makeshift  proposition,  cumbersome  and  inefficient, 
difficult  to  handle"  and  inexact  in  its  alignments.  A 
properly  built  commercial  system,  on  the  other  hand, 
will  last  at  least  for  several  seasons  of  work,  is  con- 
ducive to  rapidity  and  economy  of  construction,  and 
shows  a  finished  structure  which  is  exact  in  every 
detail. 

In  employing  a  contractor  to  build  a  silo,  the  farmer 
can,  of  course,  have  it  understood  that  he  is  to  supply 
the  materials  if  he  has  them  on  his  farm,  or  that  he  is 
to  do  the  hauling,  furnish  some  of  the  unskilled  labor, 
or  assist  in  any  other  way  of  which  he  is  capable. 

Another  advantage  in  having  this  kind  of  work 
done  by  a  contractor  is  that  the  contractor  will  have  a 


8 


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(66) 


Concrete  Silos  67 

concrete  mixer  on  the  job,  while  the  farmer  himself 
would  frequently  be  satisfied  to  mix  the  concrete  by 
hand.  On  a  structure  such  as  a  silo,  which  is  built  with 
a  comparatively  thin  wall,  and  which  at  the  same  time 
has  to  withstand  considerable  strain,  it  is  of  the  utmost 
importance  that  the  concrete  should  be  well  mixed,  so 
that  it  may  attain  its  greatest  strength. 

For  the  same  reason,  too,  considerable  care  should 
be  given  to  the  materials,  making  sure  that  they  are 
clean  and  properly  graded  to  make  a  concrete  of  the 
greatest  density.  Sand  and  gravel  for  silos  are  as 
often  as  possible  secured  from  deposits  in  the  locality, 
rather  than  being  bought  from  commercial  plants,  and 
hence  need  most  careful  inspection.  Gravel  taken 
from  a  creek  is  often  coated  with  clay  loam,  which 
prevents  the  cement  from  making  a  good  union,  and 
very  often  it  contains  particles  that  are  too  large  or  of 
a  crumbling  character.  Such  gravel  should  be  run 
over  a  screen  and  wrashed  before  using.  Soft  granite, 
shale,  slate  rock  or  dusty  cinders  are  not  desirable. 
The  material  should  not  easily  crush  and  disintegrate 
and  should  be  suitable  to  give  a  good,  strong  union 
with  the  cement.  Above  all  it  should  be  repeated  that 
it  should  be  absolutely  clean. 

In  some  localities  there  are  natural  deposits  of 
gravel  containing  varying  proportions  of  sand.  If 
clean  and  not  too  coarse,  such  gravel  is  well  suited  for 
silo  building;  but  in  using  this  material  it  is  never  safe 
to  assume  that  the  proportion  of  sand  to  gravel  is  cor- 
rect until  a  quantity  has  been  run  over  a  ^-inch  screen 
and  the  exact  proportions  determined.  Usually  such 
gravel  contains  too  much  sand. 

For  the  foundation  the  stone  may  be  as  large  as 
will  pass  through  a  2%-inch  ring,  while  for  the  main 


68  Concrete  Silos 


TABLE    VII.—  AMOUNT    OF   REINFORCING    IN    TWISTED 

?  /                                  X       p'  S                                             X         C?  <T                                                     \        -^ 

X 

. 

(/> 

'f  0 

^  0 

-      ,JP0 

~      CC    0 

<"  v 

J 

«>  6 

_       ^  o 

-     (0  O 

K« 

U 

(X  * 

a  • 

*  vfl)  fl- 

^  H1 

u 

<    ° 

-     <  t 

~            f« 

®  c^ 

f. 

CD    <V 

<0  N 

1 

10 

4 

O 

10' 

a 

Itf 

-      *) 

10' 

-       >O 

-V 

r 

i 

4r-- 

-     V 

_    Iff 

0  ° 

• 

<!>  V 

i   0 

CD   0 

i 

-  «  o 

j 

a  o 

£" 

in 

*•       ' 

~   0  CO 

h 

BJ'iO 

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'^ 

I       ,  '>o 

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K 

0 

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s 

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20' 

^ 

20' 

/?Q' 

— 

20: 

if 

0 

J 

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> 

'    O 

_     if) 

I   <  o 

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II 

§ 

10    O 

** 

(0*.. 

o 

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<Tt 
-       (DO 
.  (V 

_     CD  6 
1    - 

0 

x"1 

30' 

30' 

_3O' 

-^   ; 

-^ 

-*-^ 

-  *-# 

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I 

—      (0 
—     E 

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i- 

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Of  o 

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j 

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o 

I 

-      "?'« 

-    (0 

-  a 

c 

<D 

h 

*JJ 

_      - 

(1) 

40' 

4(f 

M 

— 

J 

4C/_ 

s 

- 

h 

3 

— 

-'-.^ 

-'^ 

E 
(ft 

~     -^ 

i 

.* 

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• 

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t-  <i 

:  i? 

* 

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5 

u" 

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<  • 

r  : 

u 

.     <. 

D  ^J 

^ 

f  K 

u.  I/J 

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M. 

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• 

8  | 

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o 

=  Y"o~ 

U<  

M 

_       0 

r"7»" 

Wf 

_<  
i 

^2 
r  «? 

If 

* 

-     '  o 

~    p) 

—    o  y 

4- 

:  'f  2 

I 

~ 

:  l\> 

-  I 

t 
ft 

A*. 

-  J,  o 

EMi 

-z  

o 

H 

I 

OL 

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*f 

P 

>5J 

AtL 

-  "^  « 

-      irt  0 
=      li 

r  »« 

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I 

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GO' 

-   9  " 

60' 

-    0 

feQ' 

60' 

—    ^ 

10  rr.  OlA.                                          I,?FT    OIA.                                                    1-4  TT.    DIA 

l&    f  T 

This  Table,  Which  Is  Adapted  From   Tables  Compiled   by   the   Reich 
in  Height.     For  Silos  of  Less  Height,   Cut  Off  the  Diagram  at   the   Figure 

Line,   Using   the   Steel   Called 


Concrete  Silos  69 

STEHL   BARS    FOR    SILOS    OP    VARIOUS    DIAMETERS. 


ao  rr.  OIA 


ert  Manufacturing-  Company,   Shows  Reinforcing-  for   Silos  Up   to   60   Feet 
Indicating    the    Desired    Height,    and    Disregard    Everything    Below    That 
for  Above   the   Line. 


70  Concrete  Silos 

wall  of  6-inch  thickness  the  size  should  not  exceed  lJ/2 
inches.  A  mixture  of  particles  of  various  sizes  from  y% 
up  to  11/2  inches  makes  the  strongest  wall. 

The  water  used  for  mixing  concrete  should  be  clean 
and  free  from  alkalis  and  acids.  It  is  especially  desir- 
able to  caution  builders  of  farm  structures  on  this 
point,  because  drainage  water  from  the  barnyard  or 
water  from  a  muddy  stream  may  sometimes  find  its 
way  into  the  supply. 

The  usual  proportions  for  a  6-inch  concrete  wall  are 
1  part  of  cement  to  2  parts  sand  and  4  parts  stone. 

In  filling  the  forms,  only  a  few  inches  in  depth 
should  be  filled  in  at  one  place  at  a  time.  Depositing  a 
great  quantity  of  concrete  at  one  place  puts  a  heavy 
strain  on  the  forms  and  has  a  tendency  to  force  them 
out  of  plumb.  As  the  concrete  is  put  into  the  form  it 
should  be  spaded  with  a  piece  of  1  by  3  inch  board, 
sharpened  to  a  bevel  edge.  The  purpose  of  the  spading 
is  to  remove  all  air  bubbles  and  avoid  the  formation  of 
cavities.  On  the  other  hand,  in  a  wet  mixture  as  used 
in  silo  building  the  spading  must  not  be  overdone,  or 
the  heavier  rock  will  sink  to  the  bottom  and  the  cement 
and  water  will  rise  to  the  top. 

The  exterior  surface  can  be  kept  smooth  by  greasing 
the  outside  form  with  soap  or  some  cheap  oil  or  grease. 
To  be  effective  this  grease  coat  must  be  renewed  at 
each  raising  of  the  forms.  No  grease  should  be  used  on 
the  inside  form,  as  this  surface  is  to  receive  a  brush 
co'at  of  pure  cement  wash.  Small  particles  of  cement 
will  adhere  to  this  form  each  time  it  is  raised,  and 
before  it  is  used  again  these  should  be  removed  with  a 
broom  or  a  wooden  trowel.  If  these  are  not  removed 
an  undue  amount  of  concrete  will  adhere,  and  this  will 
result  in  an  unnecessarily  rough  wall. 


Concrete  Silos 


71 


X*-—"  *V 

V 


Showing-  the  Difference  Between   a  Silo   That  Is  Brush   Coated 
and  One   That  Is  Not. 

As  the  forms  are  raised  the  fresh  wall  is  constantly 
exposed  to  the  drying  air  and  sun,  and  there  is  danger 
of  the  surface  drying  and  curing  too  rapidly  for  the 
interior  of  the  wall,  causing  cracks.  To  prevent  this 
the  wall  should  be  soaked  with  water  several  times  a 
day  for  several  days  and  when  possible  the  wall  should 
be  protected  with  canvas  or  burlap  thoroughly  wet. 


72  Concrete  Silos 

When  the  forms  have  been  filled  for  the  day  do  not 
smooth  the  top  with  a  trowel,  but  leave  it  as  rough  as 
possible.  A  good  plan  is  to  roughen  the  top  surface 
just  as  the  concrete  starts  to  set.  Before  putting  fresh 
concrete  on  this  wall  the  next  day,  the  top  surface 
should  be  soaked  with  water  'and  then  sprinkled  with 
raw  cement,  which  will  help  in  making  a  good  union 
between  courses.  The  forms  must  not  be  removed  for 
at  least  5  hours  after  filling. 

A  brush  coat  of  cement  wash  may  be  applied  as 
soon  as  the  form  is  raised  and  before  the  wall  has  had  a 
chance  to  dry.  This  coat  of  cement  helps  to  make  the 
wall  less  porous  and  therefore  more  nearly  air  and 
water  tight.  The  wash  is  prepared  by  mixing  together 
cement  and  water  to  the  consistency  of  thick  lime 
whitewash,  and  is  applied  with  a  whitewash  brush  in 
the  ordinary  way.  If  the  wall  has  had  time  to  dry  it 
should  first  be  drenched  with  water. 

After  this  coat  of  cement  wash  has  been  applied  the 
whole  interior  may  be  painted  with  coal  tar  thinned 
with  gasoline.  The  coal  tar  makes  the  wall  impervious 
and  also  protects  it  from  the  action  of  acids  which 
develop  in  the  silage.  It  should  be  renewed  from  year 
to  year  as  may  be  required.  The  application  of  the 
coal  tar  may  be  left  until  the  wall  is  complete,  but 
should  be  done  before  removing  the  interior  scaffold. 


CHAPTER  IX. 

THE  POLK  SYSTEM. 

This  system  of  silo  construction  is  controlled  by  the 
Polk-Genung-Polk  Company  of  Fort  Branch,  Indiana. 
It  has  as  its  basic  principle  of  operation  a  center  mast, 
erected  at  the  center  of  the  floor  of  the  structure  and 
carefully  plumbed  by  means  of  guy  wires  attached  to 
the  top  and  provided  with  turn-buckles.  From  this 
mast  everything  used  in  the  construction  of  the  silo  is 
suspended,  including  the  staging,  the  apparatus  for 
handling  the  forms,  and  the  crane  for  hoisting  and 
depositing  the  concrete. 

The  mast  is  a  four-inch  steel  pipe,  provided  with  a 
series  of  transverse  holes  to  receive  a  heavy  steel  pin. 
This  pin  supports  a  widely  flanged  collar,  which  serves 
to  support  the  jacks  by  which  the  forms  are  lifted. 

Resting  upon  the  jacks  is  a  hub,  consisting  of  a 
flanged  base  collar  and  a  top  dished  collar  connected 
by  a  central  pipe  of  sufficient  diameter  to  work  easily 
over  the  center  mast.  From  the  base  collar  of  this  hub 
radiate  steel  tees  which  are  supported  from  the  upper 
collar  by  adjustable  hanger  rods  with  chain  clevises. 

Each  form  consists  of  eight  separable  sections,  and 
each  section  is  reinforced  and  stiffened  by  a  steel  angle 
frame  around  the  edges.  The  inner  and  outer  steel 
wall-forms,  which  are  rolled  to  the  required  curvature, 
are  bolted  to  the  radiating  steel  tees.  The  outer  sec- 
tions are  bolted  together  at  their  ends  through  holes  in 
the  frames.  The  inner  sections  are  similarly  bolted 
together,  but  carry  steel  wedges  between  them,  the 

(73) 


74 


Concrete  Silos 


The  Polk  System  Equipment 


Concrete  Silos 


75 


lifting  of  which  allows  the  inner  sections  to  swing  free. 

To  keep  the  vertical  reinforcing  in  its  proper  posi- 
tion in  the  center  of 
the  wall,  small  steel 
clips  are  provided. 
The  vertical  reinforc- 
ing passes  through 

these  clips,  which  fit  I  k 

over  the  stems  of  the 
steel  tees. 

For  placing  tine 
concrete  between  the 
forms,  a  V-shaped 
dumping  bucket  is 
provided.  This  buck- 
et is  supported  by  a 
crane  pivotally  at- 
tached to  the  cen- 
ter mast  directly 
above  the  top  collar 
of  the  hub,  and  can  be  easily  swung  to  any  part  of  the 
wall  space.  It  is  hoisted  by  means  of  a  rope  and  series 
of  pulleys  so  arranged  that  the  hoisting  force  is  applied 
horizontally  from  without  the  structure.  A  small  open- 
ing, through  which  the  hoisting  rope  works,  is  cut  in 
the  wall  near  the  bottom  of  the  first  fill  of  concrete. 
When  the  bucket  is  hoisted  it  is  coupled  to  a  carrier  on 
the  crane  by  means  of  a  hinged  hook  and  is  then  swung 
to  any  part  of  the  wall  space  desired. 

The  scaffolding,  both  inner  and  outer,  is  swung  from 
the  steel  tees,  which  project  some  distance  beyond  the 
wall. 

The  operation  of  the  machine  is  very  simple.  The 
forms  are  set,  the  reinforcing  bars  are  placed  in  posi- 


Polk  System  Machine  in  Operation 


76 


Concrete  Silos 


tion,  the  concrete  is  mixed,  hoisted,  dumped  and 
packed  between  the  forms,  and  allowed  to  set.  The 
next  morning  the  nuts  connecting  the  sections  of  the 
outer  form  are  loosened,  the  steel  wedges  fixing  the 
sections  of  the  inner  form  are  lifted,  and  both  inner 
and  outer  forms  swing  free  from  the  wall.  Then,  by 
means  of  the  jacks  resting  on  the  widely  flanged  base 
collar,  the  whole  mechanism  is  lifted  until  in  position 
for  a  new  fill  and  the  forms  are  again  set  by  means  of 
the  bolts  and  wedges.  One  fill  a  day  is  the  customary 
rate  of  progress. 

These  silos  were 
originally  made  with- 
out chutes,  but  a 
chute  form  is  now  an 
integral  part  of  the 
system. 

This  chute  form  is 
carried  by  two  of  the 
steel  tees  which  are 
longer  than  the  rest 
and  is  attached  to 
the  outer  set  of 
shells,  taking  the 
place  of  one  of  the 
separable  sections.  It 
is  set  to  maintain  the 
continuity  of  the  silo 
wall  and  to  mould  a 
chute  wall  of  a  thickness  of  6  inches  where  it  joins  the 
silo  wall,  gradually  decreasing  to  4  inches  at  the  out- 
side. The  outer  shell  of  the  chute  form  is  released  and 
bolted  up  in  precisely  the  same  manner  as  the  outer 
form  of  the  machine  is  released  and  bolted  up,  the 


Twin  Silos,  16x72  Feet,  at  Dayton 
State   Hospital,    Dayton,    Ohio 


Concrete  Silos  77 

outwardly  curved  sections  forming  the  wall  imme- 
diately adjacent  to  the  silo  wall  proper  being  attached 
to  the  regular  outer  form  sections.  The  inner  form  is 
released  and  set  by  means  of  a  steel  wedge  similar  to 
those  used  between  the  sections  of  the  inner  shell 
proper. 

Provision  is  made  for  the  forming  of  doors  opening 
into  the  chute  and  for  the  construction  of  a  steel  ladder 
inside  of  the  chute.  Reinforcement  for  the  chute  is 
handled  as  in  the  silo  wall. 

The  elliptical  openings  which  are  formed  for  the 
doors  are  20x30  inches.  They  are  usually  spaced  24 
inches  apart,  but  the  number  and  arrangement  of  doors 
are  optional  with  the  builders.  The  elliptical  shape 
has  been  chosen  in  order  to  avoid  sharp  angles.  For  the 
formation  of  this  opening  a  sheet  steel  door  is  set  be- 
tween the  shells  of  the  machine  as  the  work  progresses. 
This  form  moulds  a  concrete  jamb  1  inch  in  width  and 
1/2  inch  in  depth  from  the  inner  surface  of  the  wall. 
Owing  to  the  shape  and  draft  of  the  form  the  jamb  is 
left  in  perfect  condition  for  sealing  the  door.  Imme- 
diately after  the  machine  has  passed  the  opening  the 
door  form  is  removed. 

The  door  itself  is  made  of  heavily  galvanized  sheet 
steel,  cut  to  fit  snugly  into  the  concrete  jamb  made  by 
the  form,  flush  with  the  inner  wall  and  bent  to  the 
radius  of  the  silo.  On  the  outside  of  the  door  are 
fastened  four  malleable  clips  in  which  hook  bolts  en- 
gage. Across  the  opening  on  the  outside  of  the  silo 
wooden  bars  are  placed  through  which  these  bolts  pass. 
The  desired  stress  is  obtained  by  malleable  tail  nuts. 
In  sealing  the  door  a  thin  gasket  of  moist  clay  is 
smeared  around  the  jamb  before  the  door  is  set  in 
place. 


78  Concrete  Silos 


The  silo  ladder  is  made  of  l^xl^x^  inch  steel 
angle  runners  and  lxlx%  inch  steel  steps,  the  joints 
being  electrically  welded.  It  is  secured  to  the  concrete 
wall  by  strap  screws  which  are  screwed  into  spiral 
steel  anchors  imbedded  in  the  wall  during  construc- 
tion. When  the  wall  is  completed  the  temporary  fillers 
in  the  anchors  are  removed  and  the  strap  screws  are 
firmly  inserted.  The  ladder  is  then  bolted  to  the  strap 
screws  and  is  ready  for  use.  Ordinarily  the  ladder  is 
made  up  in  10-foot  lengths,  but  sections  of  any  length 
may  be  cut. 


CHAPTER  X 

THE  MONSCO  SYSTEM 

This  is  a  system  of  construction  with  metal  forms 
controlled  by  the  Monolithic  Silo  and  Construction 
Company,  Chicago.  These  forms  are  made  of  No.  16- 
gauge  galvanized  sheet  steel  and  are  held  true  to  shape 
by  curved  steel  angle  irons  welded  to  the  sheet,  which 
reinforce  the  steel  plates  at  the  edges  and  through  the 
middle.  The  forms  are  made  in  sections  3  feet  high 
and  the  circumference  of  the  silo  is  divided  in  5  to  8 
segments,  according  to  the  size,  this  including  the  form 
for  the  chute,  which,  if  desired,  is  cast  at  the  same  time 
as  the  walls  of  the  silo.  Sufficient  forms  are  used  in 
an  outfit  to  form  two  complete  circles  around  the  silo. 

In  starting  the  construction  of  the  walls,  one  circle 
of  these  forms  is  placed  on  the  foundation  and  poured 
full.  The  next  circle  of  forms  is  then  clamped  to  these 
and  poured.  This  6  feet  will  usually  constitute  a  day's 
wort.  The  next  morning  the  bottom  circle  of  forms 
is  raised  to  the  top  and  filled,  after  which  the  section 
below  is  raised  and  filled,  this  constituting  the  second 
day's  work,  and  the  operation  is  repeated  until  the 
desired  height  is  reached.  In  other  words,  the  operator 
is  always  pouring  into  a  3-foot  section  of  mold  firmly 
clamped  to  another  3-foot  section  filled  with  concrete, 
the  concrete  set  sufficiently  to  eliminate  the  possibility 
of  a  wall  fracture. 

These  silos  have  6-inch  walls,  the  thickness  being 
the  same  from  top  to  bottom.  Forms  are  made  for 
diameters  of  10,  12,  14,  16,  18  and  20  feet. 

(79) 


80 


Concrete  Silos 


WIRET5 


-4-*-  RODS  COVERED    BY 

"  p.pe: 


Equipment  for  the  Monsco  System. 


Concrete  Silos 


81 


Completing-    a    Monsco    Silo. 

The  construction  is  carried  on  by  means  of  a  center 
mast  of  steel,  this  mast  carrying  a  steel  frame  for 
staging  and  also  a  revolving  derrick  carrying  the 
buckets,  by  means  of  which  the  concrete  is  elevated 
and  deposited.  The  elevation  on  the  mast  of  both  the 
staging  and  derrick  are  under  control  of  the  men  on 
the  staging,  so  that  they  can  be  readily  moved  up  as 
the  construction  proceeds.  The  mast  and  staging 


82 


Concrete  Silos 


Section    of    Mold 


Chute. 


frame  are  entirely  separate  from  the  wall  forms,  the 
latter  depending  entirely  for  support  on  the  3  feet  of 
wall  when  closed  by  the  lower  circle  of  forms ;  and  as 
the  upper  section  of  the  staging  frame  is  always  above 
the  wall  forms  the  same  outfit  will,  of  course,  answer 
for  varying  diameters  of  silos. 

These  silos  are  reinforced  with  triangle  mesh  rein- 
forcing, the  selection  of  the  reinforcing  depending 
upon  the  size  of  the 
silo  and  being  selected 
usually  to  provide  suf- 
ficient strength  with- 
out placing  any  addi- 
tional wires.  The 
company  recommends 
a  38-inch  width,  this 
allowing  a  2-inch  lap 
between  courses.  After  a  circle  has  been  poured  and 
it  is  desired  to  move  up  the  lower  section  of  the  forms, 
the  bucket  at  the  end  of  the  derrick  is  taken  off  and 
a  wooden  seat  is  suspended  from  the  hook  in  its  place. 
By  this  means  a  man  is  lowered  to  the  outside  of  the 
forms  and  removes  the  clamps  which  hold  the  two 
sections  together.  The  forms  are  drawn  up  by  men 

on  the  scaffold 
by  means  of 
hooks  which 
engage  in  holes 
in  the  angle 
iron  welded  to 
the  top  of  the 
forms.  The  in- 

Monsco    Roof    Form. 

side  forms  are 
m  a  n  i  pulated 


Concrete  Silos  83 

from  a  small  auxiliary  platform  suspended  below  the 
main  platform  of  the  scaffold.  As  the  construction  is 
carried  up,  the  mast  is  raised  'by  means  of  two  cast-steel 
worm-geared  winches. 

The  door  on  this  silo  is  of  the  continuous  type.  It 
has  a  gas  pipe  running  through  the  concrete  on  each 
side,  and  around  which  the  ladder  irons  are  engaged. 
The  gas  pipe  has  several  strands  of  wire  extending 
around  it  at  frequent  intervals  and  running  back  into 
the  concrete  2  or  3  feet  in  order  to  provide  a  sufficient 
anchorage.  The  doors  themselves  are  of  wood. 

A  special  roof  form,  making  a  concrete  roof,  with 
dormer,  is  also  supplied  if  desired. 


CHAPTER  XI 

THE  EEICHEKT  SYSTEM 

This  is  a  system  of  monolithic  construction  devel- 
oped by  the  Reichert  Manufacturing  Company  of  Mil- 
waukee. It  differs  from  other  systems  of  this  type  in 
that  the  forms  are  made  in  sections  24  inches  square, 
instead  of  in  larger  sections,  so  that  each  can  be  handled 
easily  by  one  man.  The  small  size  also  makes  for  ad- 
justability, a  feature  which  is  still  further  provided  for 
by  the  fact  that  the  sections  are  reinforced  at  top  and 
bottom  with  strap  steel  instead  of  angles,  thus  allowing 
them  to  take  the  curvature  of  the  particular  size  of  silo 
under  construction,  to  which  they  are  then  held  by  a 
rigid  inner  steel  circle  and  by  spacers  placed  at  suit- 
able intervals.  Silos  of  all  diameters  are  thus  made 
with  the  same  outfit,  except  that  fractional  plates  have 
to  be  used  to  fill  out  for  the  various  sizes  where  the 
circumference  does  not  work  out  in  exact  multiples  of 
24  inches. 

An  outfit  consists  of  sufficient  forms  for  three  rings 
around  the  silo.  This  is  enough  for  one  day's  run, 
or  6  feet  in  height,  the  practice  followed  by  most  con- 
tractors in  using  this  system,  although  some  are  erect- 
ing 8  feet  per  day. 

The  sections  are  reinforced  vertically  with  angle 
irons,  and  when  assembled  the  vertical  joints  are  se- 
cured by  clamps.  These  clamps  are  attached  to  one 
angle  of  each  section  and  when  in  place  fit  down  over 
the  angle  of  the  adjoining  section,  a  push  of  the  lever 
driving  them  up  tight.  These  levers  are  downward  act- 

(84) 


Concrete  Silos 


85 


ing,  so  that  when  it  is 
desired  to  release 
them  a  jerk  with  the 
hook  from  above  is 
all  that  is  necessary. 

Each  section  is 
joined  to  the  one 
above  it  by  a  hook  at- 
tached to  the  upper 
edge  of  the  lower  sec- 
tion, which  hooks 
over  a  raised  rivet  on 
the  lower  edge  of  the 
section  above.  This 
hook  is  pivoted  and 
has  a  hole  in  the 
shank,  so  that  a  work- 
man above,  after  rais- 
ing the  side  clamps 
with  a  long  hook, 
which  is  a  part  of  the 
outfit,  can  insert  the 
point  of  the  hook  in 
the  shank  of  the  hook 
on  the  lower  form, 
with  one  operation 
disengaging  the  form 
from  the  one  above  it 
and  drawing  it  up 
into  its  new  position. 

There  is  in  this  sys- 
tem a  center  mast  of 
steel  tubing,  carrying 
collars  which  can  be 


Reichert  Silo  With  Square  Chute 


86  Concrete  Silos 

moved  up  'as  the  work  progresses  and  to  which  the  radial 
staging  arms  are  attached.  There  are  two  sets  of  these 
arms.  The  upper  platform  is  flush  with  the  top  of  the 
silo,  from  which  the  forms  are  manipulated  arid  the  pour- 
ing is  done.  Each  of  these  arms  consists  of  two  angle 
irons  telescoped  on  each  other  and  with  bolt  holes  at 
suitable  intervals,  so  th'at  they  can  be  adjusted  to  the 
various  diameters  it  is  desired  to  build.  At  one  end  they 
rest  in  slots  in  the  collars  on  the  mast,  and  at  the  other 
end  they  rest  on  the  circles  of  angle  iron  which  are  car- 
ried right  up  with  the  forms  to  give  them  their  true 
shape.  These  circles  are  made  in  segments  for  easier 
handling,  but  can  be  rigidly  clamped  together  for  use. 

The  upper  ring,  which  holds  the  forms  in  shape,  also 
c'arries  a  single  track  on  which  run  the  two  wheels  of  a 
small  car.  This  car  rests  on  a  frame  attached  to  a  loose 
collar  around  the  mast  and  just  above  the  collar  which 
carries  the  upper  platform.  It  thus  can  be  pushed 
around  to  any  p'art  of  the  circle  desired,  swinging 
around  the  mast  as  a  pivot  and  the  outer  end  carried  by 
the  wheels  on  the  track.  This  car  is  merely  a  frame 
with  bearings  on  which  the  bucket  of  concrete  can  be  set 
when  it  is  brought  up  from  below,  the  arrangement  being 
such  that  it  can  be  tilted  to  dump  into  the  forms,  a  steel 
apron  being  attached  to  the  'car  to  direct  the  flow  into 
the  forms  and  prevent  loss  of  concrete. 

A  derrick,  also  attached  to  the  mast  in  the  center, 
by  which  all  materials  are  handled,  completes  the 
outfit. 

The  ordinary  wall  thickness  in  this  system  is  6 
inches,  though  the  adjustability  is  such  that  almost  any 
desired  thickness  can  be  obtained,  the  only  additional 
parts  of  the  outfit  needed  being  spacers  for  the  desired 
thickness  and  perhaps  additional  fractional  plates  in 


Concrete  Silos 


87 


order  to  make  the  outside  ring  fit  the  change  of  circum- 
ference. 

Two  types  of  chute  are  provided  for:  a  square 
chute  is  made  with 
the  ordinary  flat 
wall  sections  made 
by  the  Reichert 
Manufacturing  Com- 
pany, or  a  curved 
chute  made  with 
special  sections  pro- 
vided for  the  pur- 
pose. This  System  COn-  Completing  a  Conical  Roof 

templates  the  use  on  a  continuous  door,  and  door  frames 
are  provided  with  the  outfit,  to  be  set  into  the  forms. 
They  are  slotted  to  carry  the  ladder  irons.  Intermittent 
door  forms  -can  also  be  supplied  if  desired. 

Reichert  metal  roof  molds  are  made  in  two  types. 
One  of  these  is  a  dome  roof,  the  form  consisting  of 
curved  segments  which  rest  on  the  silo  wall  proper  and 
are  locked  to  a  hub  at  the  top.  The  angles  of  the 
separate  sections  fit  into  slots  in  the  hub,  thus  locking 
the  entire  equipment 
together.  The  other 
type  of  roof  consists 
of  straight  segments 
resting  on  the  side 
walls  and  bolted  to  a 
ring  at  the  top.  The 
roof  molds  include 
complete  equipment 

for  making  cornice  and  dormer  window.  No  part  of  the 
mold  is  left  in  the  structure,  all  being  taken  away  and 
used  repeatedly. 


Form  Assembled  for  a  Dome  Roof 


88  Concrete  Silos 

The  reinforcing  used  in  the  Reichert  silos  is  either 
Triangle  mesh  or  square  twisted  steel  bars.  The  mesh 
is  used  according  to  the  table  of  the  American  Steel 
and  Wire  Company,  as  given  on  page  66.  The  bars  are 
placed  according  to  individual  plans  for  each  size  as 
drawn  up  by  the  Reichert  Manufacturing  Company. 
Table  VII,  on  page  68,  gives  in  somewhat  shortened 
form  the  scheme  of  reinforcing  with  bars  as  used  by 
this  company. 


CHAPTER  XII 


OTHER  MONOLITHIC  SYSTEMS 

Peerless  Silo  Molds.  These  molds  are  controlled  by 
the  New  Enterprise  Concrete  Machinery  Company, 
First  National  Bank  Building,  Chicago.  They  are  made 
of  sheet  steel,  reinforced  with  iron  frame,  and  are  suffi- 
ciently flexible  so  that  various  diameters  of  silos  can  be 
made  with  the  same  forms  by  using  smaller  plates  to 
bring  them  to  the  proper  circumference.  The  inside 
form  is  a  No.  16 
steel  and  the  outside 
form  is  a  No.  18.  The 
chute  is  poured  at  the 
same  time  as  the  main 
body  of  the  silo  wall. 

The  unusual  fea- 
ture of  this  system  is 
the  combined  derrick 
and  scaffold  which 
rests  upon  the  con- 
crete wall,  doing 
away  with  the  necessity  of  building  up  staging  from 
the  ground.  The  derrick  and  staging  are  raised 
by  four  small  jacks  or  raising  devices,  stationed 
at  the  quarter  points  of  the  circumference,  with  a  man 
at  each  jack.  By  this  means  the  derrick-scaffold  is 
raised  first,  before  the  forms  are  drawn  up  into  place. 

These  molds  have  a  daily  capacity  of  5,  6,  or  7% 
feet,  depending  on  the  number  and  type  used.  The  6- 
foot  molds  are  made  in  two  rings  of  3  feet  each.  The 


Peerless    Outfit. 


(89) 


90 


Concrete  Silos 


Peerless   Silos   at   State    School,    Lincoln,    111. 
Dimensions,  17x50  Feet. 


usual  custom  at  present,  however,  is  to  use  3  rings  of 
2%  feet  each,  thus  building  7%  feet  of  wall  each  day. 
Molds  are  built  for  a  5-inch  wall  unless  otherwise 
preferred. 

Triangle  mesh  is  used  throughout  for  reinforcing. 
Metal  doors  and  door  frames  of  the  continuous  type, 


Concrete  Silos 


91 


Peerless  Outfit. 


First  Ring-  of  Mold  Filled  and  Derrick  Raised 
to    Receive    Second    Ring. 


and  either  metal  or  concrete  roof  are  included  in  the 
construction  of  these  silos. 

Martin  Adjustable  Steel  Silo  Forms.  These  forms 
are  made  and  sold  by  the  Martin  Concrete  Form  Com- 
pany, Ottawa,  Kan.  They  build  silos  from  12  to  20 
feet  in  diameter. 

The  outside  form  is  made  of  14-gauge  steel  and  the 
inside  form  is  made  of  12-gauge  steel.  The  top  and 
bottom  of  the  inside  form  are  held  in  place  by  angle 
iron  braces  radiating  from  the  center.  Each  section 
of  the  inside  form  is  adjustable  to  a  larger  or  smaller 
circle  by  means  of  turnbuckles.  The  size  of  the  form 
is  also  changed  by  adding  sections  and  adjusting  the 


92 


Concrete  Silos 


curvature  of  each  section.     The  ends  of  each  section 
are  made  with  slideable  edges  and  are  provided  with 
turnbuckles  for  con- 
tracting and  expand- 
ing the  forms. 

The  form  is  raised 
by  means  of  jacks 
operated  from  the 
platform.  The  rein- 
forcing rods  run 
through  the  jacks. 
At  the  bottom  of 
the  jack  is  a  collar 
clamped  to  the  rein- 
forcing rod  which 
supports  the  jack. 
The  extension  yoke 
which  is  attached  to 
the  inside  and  out- 
side form  is  bolted  to 
the  stationary  nut  of 
the  jack.  By  turning 
the  screw  the  nut  is 
pushed  up,  pulling 
the  form  with  it. 

These  forms  pro- 
vide for  building  6 
to  10  feet  of  wall  in 
height  per  day. 

Intermittent  metal  doors  are  used  in  this  system. 
They  are  20x22  inches  in  size,  and  are  made  entirely  of 
cast  iron  except  the  hinges,  which  are  mild  steel.  The 
frames  are  also  of  cast  iron,  and  carry  a  groove  for 


Building'   a   Silo    with   Martin   Forms 


Concrete  Silos 


93 


felt   packing.      They    are   set   into   the   forms    as   the 
concrete  is  poured. 

Van  Guilder  System.     This  system,  which  is  con- 
trolled by  the   Van  Guilder  Hollow  Wall   Company, 


Van  Guilder  Hollow  Wall  Form 

Rochester,  N.  Y.,  makes  a  silo  with  either  a  single  or 
a  double  wall.  Either  type  is  made  with  a  small 
machine,  as  shown  in  the  illustration,  which  is  set  on 
the  footings  tamped  full  of  concrete,  then  removed  and 
carried  around  to  a  new  position,  the  operation  con- 


94  Concrete  Silos 

tinuing  until  a  complete  circle  has  been  made.  The 
machine  is  then  set  on  the  section  of  wall  thus  made 
and  another  section  is  carried  around  in  the  same  way. 
The  double  wall  machine  makes  a  4-inch  air  space  and 
the  walls  are  adjustable  for  thickness  of  from  4  to  6 
inches.  The  single  wall  machine  can  be  adjusted  to 
make  walls  from  5  to  8  inches  thick.  The  machine  is 
not  adjustable  to  different  diameters  of  silos. 

The  Conklin  System.  Made  by  the  Conklin  Construc- 
tion Company,  Hartford,  Mich.  The  molds  are  of 
No.  16  black  sheet  steel  held  in  shape  by  l^xl^ 
angles  riveted  on.  The  inside  forms  are  also  reinforced 
with  l1/^  inch  channel  steel  in  the  center  to  keep  them 
from  buckling.  The  forms  are  made  in  sections  4  feet 
high,  and  two  complete  circles  constitute  an  outfit, 
sufficient  for  a  day's  work  of  8  feet  of  wall. 

The  hoist  is  operated  on  a  center  mast  of  a  4-inch 
gas  pipe  and  in  10-foot  lengths  with  slip  joints.  One- 
inch  holes  are  drilled  at  proper  distances  through  the 
center  mast  for  1-inch  pins.  The  jack  bench  and  spider 
hub  rest  on  the  pins  through  the  center  mast. 

There  are  eight  tee  irons  radiating  from  the  spider 
hub  and  supported  by  rods  and  chains  from  the  casting 
above.  The  rods  and  chains  are  adjustable.  On  the 
ends  of  the  tee  irons  are  adjustable  tee  irons  or  arms 
that  may  be  taken  up  or  let  out  for  the  different  sizes 
of  molds.  Boards  are  laid  on  the  tee  irons  to  make  a 
scaffold  for  the  men  to  operate  the  machine. 

From  every  other  tee  iron  are  suspended  %-inch 
rods  (4  in  all)  to  hold  two  timbers  (2x6  inches),  on 
which  a  scaffolding  is  built  completely  over  the  inside 
of  the  silo.  The  men  stand  on  that  scaffold  and  do 
their  work  inside  the  job. 


Concrete  Silos  95 

The  boom  is  supported  by  two  %-inch  rods  with 
turnbuckles  which  swing  around  the  center  mast.  It 
carries  a  car  or  traveler  which  carries  the  hoisting 
cable  and  cement  bucket. 

The  derrick  is  also  used  as  a  means  of  support  for 
the  workman  who  uncouples  the  outer  forms  when 
they  are  moved  up. 

A  sufficient  area  of  steel  is  provided  in  the  cross 
wires  of  triangle  mesh  reinforcement  to  prevent  tem- 
perature cracks,  thereby  eliminating  the  necessity  of 
laying  additional  reinforcement  at  right  angles  to  the 
longitudinal  or  tension  members.  The  common  width 
is  54  inches.  This  allows  for  a  6-inch  lap  on  each  4-foot 
section  poured. 

The  -Conklin  silos  are  equipped  with  continuous 
doors,  30x30  inches,  of  1-inch  lumber,  with  tar  paper 
between,  with  felt  gasket  between  door  and  cement. 
The  doors  are  set  in  a  2-inch  cement  jamb,  forming  a 
solid  construction.  Ladder  irons  are  placed  about 
every  30  inches,  made  of  1-inch  mild  steel. 

The  Conklin  equipment  is  adapted  to  build  the  non- 
continuous  type  of  doorway  by  leaving  out  the  steel 
forms  for  blocking  off  the  continuous  doorway  and 
adding  the  special  form  in  the  chute  for  making  the 
non-continuous.  By  using  this  special  form,  any  style 
of  door  (elliptical  or  square)  can  be  used,  by  placing 
the  door  form  between  the  special  chute  form  and  the 
inside  silo  form. 

The  2-E  Flexible  Silo  Form.  This  form  is  5  feet  in 
length  and  build  either  a  hollow  or  solid  wall.  In 
building  the  silo  the  form  is  placed  on  the  foundation 
and  filled  and  tamped,  then  moved  to  a  new  location 
and  filled  again,  the  operation  being  repeated  until  the 


96  Concrete  Silos 

entire  circle  is  completed.  The  courses  are  10  inches 
high.  The  form  is  sold  by  M.  L.  Schluetter,  223  West 
Illinois  Street,  Chicago. 

Blumer's  Perfect  Silo  Forms.  These  are  galvanized 
iron  forms  reinforced  with  angle  irons  and  made  in 
large  segments  so  that  two  or  three  large  sections,  pos- 
sibly with  a  small  filler,  will  make  a  complete  circle 
around  silo.  Bracing  rods  are  attached  to  the  inner 
sections,  across  which  plank  may  be  placed  for  work- 
men to  stand  upon  while  drawing  up  sections  or  filling 
in  with  concrete.  These  forms  are  sold  by  St.  Jacobs 
Lumber  and  Hardware  Company,  St.  Jacobs,  111. 


CHAPTER  XIII 
THE  PIT  SILO 

Instead  of  being  built  above  ground,  as  is  the  ordi- 
nary fashion,  a  silo  may  consist  of  a  hole  excavated  in 
the  earth  and  plastered  with  cement  mortar.  This  is 
known  as  the  Pit  Silo. 

This  type  of  silo  has  apparently  but  one  advantage, 
and  that  is  the  advantage  of  cheapness.  A  pit  silo  is 
not  to  be  considered  as  a  permanent  improvement.  If 
it  is  necessary  to  put  in  a  temporary  expedient,  how- 
ever, as  is  the  case  of  a  tenant  on  a  farm,  who  would 
in  many  cases  not  be  justified  in  going  to  the  expense 
of  building  a  permanent  silo,  the  pit  silo  will  do  very 
well.  In  fact  it  will  fulfill  its  purpose  much  better 
than  the  wood  silo,  the  only  other  type  of  construction 
which  would  be  considered  under  such  circumstances, 
and  is  usually  much  cheaper  as  well. 

It  must  be  borne  in  mind,  however,  that  it  is  not 
practicable  to  build  pit  silos  in  all  localities.  They 
can  be  built  to  advantage  only  in  soil  which  has  a  low 
water  level,  so  as  to  preclude  the  possibility  of  damp- 
ness in  the  silo. 

The  depth  of  20  feet  is  considered  about  the  limit 
of  practicability  for  such  a  silo  in  any  event  because  of 
the  difficulty  of  removing  the  silage;  but  it  should  not 
go  to  this  depth  if  there  is  a  possibility  of  striking 
water.  Of  course  it  would  be  possible  to  seal  a  structure 
effectually  against  moisture,  even  at  a  considerable 
head ;  but  this  would  be  an  expense  which  such  a  struc 
ture  would  not  justify,  it  being  much  better  to  expend 
the  money  on  an  above-ground  silo. 

(97) 


98  Concrete  Silos 

While  silage  will  keep  very  well  in  a  pit  silo  if  the 
silo  is  made  moisture  proof,  there  is  one  insurmountable 
objection  to  this  form  of  silo  as  above  suggested,  and 
that  is  the  difficulty  of  getting  the  silage  out.  The 
advocate  of  this  form  of  construction  will  say  that  this 
is  offset  in  a  measure  by  'the  ease  with  which  the  pit 
silo  is  filled;  but  when  it  is  considered  that  the  filling 
is  done  in  favorable  weather,  while  the  silage  is  re- 
moved during  the  winter,  this  does  not  constitute  as 
great  an  offset  as  might  at  first  appear.  Furthermore, 
there  is  a  tendency  in  constructing  the  pit  silo  to  rely 
entirely  too  much  on  the  stability  of  the  ground,  simply 
giving  a  plaster  coat  to  form  a  smooth  interior  wall. 
This  plaster  will  crack  sooner  or  later,  depending  on 
the  condition  of  the  soil;  while,  if  the  builder  goes  to 
to  the  trouble  of  preparing  an  inner  form  and  pouring 
a  substantial  monolithic  wall,  this  expense,  added  to 
the  cost  of  excavation,  will  show  little  gain  over  an 
above-ground  silo. 

In  the  case  of  pit  silos  it  must  also  be  remembered 
that  there  is  a  possibility  of  carbon  dioxide  gas  collect- 
ing in  the  bottom  and  making  it  dangerous  for  persons 
to  enter.  This  gas  is  apt  to  form  in  larger  quantities 
within  a  day  or  two  after  the  filling  begins,  so  that  if 
it  is  necessary  to  partially  fill  the  silo  and  then  let  it 
stand  for  a  time,  a  lighted  lantern  should  be  lowered 
into  the  pit  before  entering  it.  If  it  is  found  to  contain 
gas,  running  the  cutter  for  a  few  minutes  and  empty- 
ing its  contents  into  the  silo  will  usually  set  up  a  suffi- 
cient current  of  air  to  carry  the  gas  away. 

There  are  three  types  of  pit  silos:  Plain  holes  in 
the  ground,  where  the  walls  are  plastered  and  the  silage 
is  cropped  in  and  lifted  out  at  the  top;  holes  in  the 
ground,  but  with  the  silo  extended  above  the  ground 


Concrete  Silos  99 

from  4  to  12  feet,  the  roof  placed  above  this,  and  the 
silage  removed  through  the  side  of  the  upper  part; 
silos  built  similar  to  either  of  the  other  two,  but  set  in 
the  bank  so  that  retaining  wails  which  act  as  a  chute 
are  placed  up  and  down  beside  a  line  of  doors.  If  there 
is  a  bank  barn  and  the  retaining  walls  connect  the  silo 
to  the  barn,  the  conditions  are  ideal. 

Of  the  three  types  of  pit  silos  mentioned  above,  the 
last  is  the  most  convenient,  also  the  most  expensive. 
The   first  is  the   cheapest 
and  likewise  the  least  con- 
venient. 

Most  silos  are  con- 
structed by  commencing 
at  the  bottom  and  build- 
ing up;  but  a  pit  silo  can 
be  constructed  by  com-  section  Through  Pit  sno 
mencing  at  the  top  and 

building  down.  By  building  a  silo  in  this  manner,  the 
ground  a-cts  as  a  staging  and  no  lumber  or  labor  is  re- 
quired for  that  purpose. 

The  first  step  in  the  construction  of  a  pit  silo  con- 
sists in  affording  sufficient  protection  to  the  edge  of  the 
excavation  to  prevent  crumbling  or  caving.  An  exact 
circle  should  be  marked  out  on  the  ground  of  the  size 
of  the  proposed  excavation.  Immediately  outside  of 
this  circle  a  trench  should  be  excavated  not  less  than 
18  inches  deep  and  not  less  than  1  foot  wide.  This 
trench  should  be  filled  with  concrete  properly  made. 
As  soon  as  the  concrete  in  the  trench  has  set  and  suffi- 
ciently hardened  the  excavation  may  be  proceeded  with. 

A  hay  carrier  track  should  be  arranged  above  the 
proposed  excavation  at  sufficient  height  so  that  the  dirt 
from  the  carrier  may  be  dropped  into  a  wagon  placed 


100  Concrete  Silos 

for  the  purpose  of  receiving  it.  This  track  should  have 
an  upward  slope  toward  the  wagon  so  that  when  the 
carrier  is  unloaded  it  will  return  of  its  own  weight  to 
the  stop,  which  should  he  placed  exactly  above  the 
middle  of  the  silo. 

The  carrier  is  best  made  of  a  strong  box  with  a 
hinged  bottom,  with  a  fastening  that  may  be  easily 
secured  and  easily  loosened.  This  may  be  attached  to 
the  hay  carrier  by  chains  or  ropes  so  arranged  that  the 
box  when  loaded  will  b'alance.  A  horse  on  the  end 
of  the  tackle  rope  or  -a  gasoline  engine  with  a  lifting 
appliance  will  do  the  lifting.  When  this  appliance  is 
arranged  in  a  satisfactory  manner  it  becomes  an  easy 
matter  to  take  care  of  the  earth  from  the  excavation. 

The  excavation  should  be  made  in  such  a  way  that 
the  walls  are  perpendicular  and  smooth.  When  the 
excavation  has  been  carried  to  about  10  feet  (and  this 
distance  is  chosen  because  experience  has  proved  that 
it  is  most  satisfactory  for  the  purpose),  the  walls  of  the 
excavated  part  should  be  given  a  good  coating  of  the 
best  cement  concrete  mixture.  This  should  consist  of 
not  less  than  1  part  of  Portland  cement  to  2%  parts  of 
screened  sand.  The  sand  should  be  sharp,  not  too 
coarse,  and  free  from  'clay.  The  first  coat  should  be 
left  rough,  and  the  second  coat  immediately  applied 
before  the  first  coat  hardens.  In  order  that  this  work 
may  be  well  done,  it  is  best  to  employ  an  experienced 
mason  for  this  purpose.  The  first  two  coats  should 
constitute  a  single  coating  not  less  than  %-inch  in 
thickness.  When  this  coat  has  had  sufficient  time  to 
harden  enough  to  be  protected  against  injury,  the  ex- 
cavation may  be  continued  to  another  depth  of  10 
feet,  and  the  plastering  repeated. 


Concrete'Silos 


•101 


It  is  well  to  provide  for  some  drainage  at  the  bot- 
tom of  the  silo.  This  may  be  done  in  the  following 
manner:  When  the  excavation  is  finished  the  earth 
floor  of  the  silo  should  slope  toward  the  center.  Here 
a  hole  should  be  dug  large  enough  to  receive  a  drain- 
age tile  30  inches  long  of  any  desired  diameter.  The 
drainage  tile  should  be  inserted  in  this  hole,  and  cov- 
ered with  an  iron  grating  with  a  mesh  sufficiently 
small  to  be  a  protection  against  rodents.  The  bottom 
should  then  be  covered  with  cement  in  the  same  man- 
ner that  the  sides  are  covered,  and  this  cement  should 
join  the  grating  and  hold  it  in  place.  Any  moisture 
that  accumulates  in  the  silo  may  in  this  manner  be 
drained  off,  preventing  both  annoyance  and  waste. 

For  convenience,  it  is  better,  after  the  silo  has  been 
finished,  to  put  a  masonry  extension  above  ground  for 
a  distance  of  at  least  4  feet,  with  a  door  upon  one 
side  through  which  the  carrier  used  in  removing  silage 
may  pass.  This  extension  may  be  built  of  poured  con- 
crete, providing  forms  can  be  made  for  the  purpose, 
or  it  may  be  made  of  concrete  blocks  properly  con- 
structed, or  of  any  material  that  to  the  builder  seems 
most  desirable. 

A  roof  should  be  provided,  and  this  should  be  made 
in  such  a  manner  as  to  allow  the  free  use  of  the  car- 
rier and  track  that  are  used  in  removing  the  silage. 

If  it  is  desired  to  give  the  pit  silo  somewhat  more 
stability  than  can  be  attained  by  plastering  on  the 
bare  ground,  a  metal  fabric  can  be  used  and  the  plas- 
ter coat  placed  on  this.  Stakes  can  be  driven  into 
the  earth  walls  of  the  silo  and  the  metal  fabric  fas- 
tened to  these  stakes. 


CHAPTER  XIV 

THE  METAL  LATH  SILO 

The  construction  of  the  metal  lath  silo  has  been 
treated  in  considerable  detail  by  Mr.  Geo.  C.  Wheeler, 
specialist  in  animal  husbandry  of  the  Kansas  State 
Agricultural  College,  Manhattan,  Kans.,  in  an  article 
published  in  a  bulletin  of  that  institution.  This  article 
has  also  been  reprinted,  with  slight  modifications,  by 
the  Northwestern  Expanded  Metal  Company,  of  Chi- 
cago, and  we  can  do  no  better  than  to  follow  quite 
closely  the  information  there  given. 

The  first  round  of  the  metal  lath  which  forms  the 
chief  reinforcement  of  this  silo  must  have  its  edge  em- 
bedded 5  or  6  inches  in  the  top  of  the  foundation,  in 
order  to  insure  a  perfect  union  between  the  foundation 
and  the  wall  proper.  When  the  footing  trench  has 


Cross  Section  of  Foundation  of  HY-RIB  Silo. 

been  filled  to  within  about  6  inches  of  the  top  and  the 
concrete  brought  to  an  approximate  level,  the  lath, 
which  comes  in  strips  8  feet  long  and  18  inches  wide, 

(102) 


Concrete  Silos  103 

should  be  stood  on  edge  on  this  base  and  concrete 
should  be  poured  on  both  sides  of  it.  Its  position 
should  be  on  a  circle  having  a  radius  2  inches  greater 
than  the  inside  radius  of  the  finished  silo.  The  strips 
of  lath  should  be  lapped  about  3  inches  at  the  ends. 
When  the  circle  is  completed,  the  wall  outside  of  the 
lath  should  be  carefully  leveled.  In  eight  or  ten  hours 
the  dirt  inside  of  the  foundation  wall  may  be  thrown 
out  to  within  10  or  12  inches  of  the  bottom  of  the 
concrete. 

In  building  this  type  of  silo  it  is  necessary  to  erect 
on  the  inside  a  scaffold  of  at  least  four  platforms  be- 
fore any  other  work  can  be  done.  It  is  very  important 
that  this  scaffold  be  so  constructed  that  the  plank  run- 
ways of  the  four  platforms  shall  be  at  a  uniform  dis- 
tance from  the  wall  of  the  silo.  In  silos  14  feet  or 
greater  in  diameter,  a  six-legged  scaffold  is  used.  For 
a  12-foot  silo  a  scaffold  of  only  four  legs  is  needed.  In 
order  to  place  this  scaffold  properly  there  should  be 
marked  on  the  floor  of  the  excavation  a  circle  having  a 
radius  2  feet  less  than  the  radius  of  the  silo.  The  six 
legs  of  the  scaffold,  granted  that  a  six-legged  one  is  to 
be  used,  should  stand  on  this  circle  and  should  be  equi- 
distant from  each  other.  The  distance  will  be  equal 
to  the  radius  of  the  circle  upon  which  they  stand;  the 
sweep  used  in  marking  this  circle  may  therefore  be 
used  as  a  measure,  marking  the  place  for  each  leg  to 
stand  on  the  circle  until  the  six  points  are  located.  It 
will  be  much  more  convenient  to  have  the  door  open- 
ing of  the  silo  come  between  two  legs  of  the  scaffold 
than  directly  opposite  one. 

All  the  crosspieces  should  be  of  2x4  material  and  of 
such  length  as  to  extend  at  least  a  foot  outside  the 


104  Concrete  Silos 

legs  of  the  scaffold.  The  planks  to  form  the  runway 
on  the  outside  should  be  of  2x8  material,  and  in  a  silo 
16  feet  in  diameter  should  be  8  feet  long.  If  the  silo 
is  to  be  36  or  37  feet  high,  it  will  be  necessary  to  make 
five  platforms.  It  is  convenient  to  have  the  top  plat- 
form come  within  3  or  4  feet  of  the  top  of  the  silo,  since 
the  work  of  raising  the  2x4's  and  nailing  the  plate  on 
top  is  done  from  this  platform. 

The  following  table  shows  dimensions  of  plate  seg- 
ments and  number  required  for  silos  of  different  sizes : 

Inside 
diameter  of 

silo 

12  feet 
14  feet 
16  feet 
]8  feet 

The  plate  is  sawed  from  Ix6-inch  material,  which 
should  be  either  fir  or  cypress.  The  plan  of  making 
the  pattern  is  shown  in  the  plate.  A  piece  of  the  6-inch 
board  should  be  securely  fastened  to  a  work  bench  or 
barn  floor, 
and  after  the  U  V  B  / 


Dimensions 

No.  of 

of  segment 

segments 

Radius 

C.  D. 

required 

2  ft.,  10  1/2  in. 

26 

6  feet 

3  ft.,     4  1/5  in. 

26 

7  feet 

3  ft.,  10          in. 

26 

8  feet 

3  ft.,     9          in. 

30 

9  feet 

distance  C-D      JLUu-^" 
has  been  de- 
t  e  r  m  i  n  e  d 
from    the 


table,       these  Detail  of  Plate. 

points  should  Be  carefully  marked  upon  one  edge  of  the 
board.  Locate  the  center  of  the  desired  curve  by  the 
use  of  a  sweep,  through  which  two  small  nails  have  been 
driven,  the  distance  between  them  being  exactly  the  in- 
side radius  of  the  silo.  Using  C  and  D  as  centers,  de- 
scribe intersecting  arcs,  thus  locating  the  desired  center. 
Drive  one  nail  of  the  sweep  at  the  intersection  of  these 


Concrete  Silos  105 

arcs.  With  the  other  nail  mark  the  curve  on  the  1x6- 
inch  board.  With  a  straight-edge,  extend  the  radius 
across  the  board,  locating  the  lines  at  ends  of  board  for 
sawing  off,  as  shown  by  dotted  lines  in  the  plate.  This 
pattern  should  be  carefully  sawed  out  and  used  in 
marking  out  the  rest  of  the  segments  necessary.  These 
plate  pieces  are  to  be  doubled  and  the  joints  broken  as 
the  plate  is  built  up. 

In  order  to  cast  the  posts  or  door  jambs  for  the  con- 
tinuous door  opening  used  in  this  type  of  silo  and  to 
properly  hold  the  reinforcing  in  place,  a  form  must  be 
constructed  extending  the  full  height  of  the  silo  above 
the  foundation.  One  of  the  plates  gives  the  details  of 
construction  of  this  form.  The  6-inch  boards  should  be 
scribed  the  full  length,  1%  inches  from  the  outside 
edge.  Beginning  at  the  bottom,  the  points  for  the  rods 
should  be  located  26  inches  apart  on  this  line.  Holes 
should  be  bored  at  each  one  of  these  points  with  a  bit 
1/16-inch  larger  than  the  size  of  the  rods  to  be  used. 
These  6-inch  boards  are  then  ripped  apart  upon  this 
line. 

The  next  step  is  to  nail  together  the  8-inch  board 
C  and  the  wider  part  of  the  6-inch  board  A.  Five  or 
six  pieces  of  6-inch  board  (E  in  the  plate),  should  now 
be  sawed  and  nailed  to  the  underside  of  the  8-inch 
boards,  care  being  taken  that  the  two  sides  of  the 
form  are  squared  with  each  other  before  these  boards 
are  nailed  into  place.  To  insure  a  uniform  distance 
between  the  posts  when  the  form  is  completed  a  gauge 
18  inches  long  should  be  prepared  and  used  between 
the  two  halves  of  the  form  during  this  nailing.  The 
2x2 's,  which  have  been  dressed  out  and  sawed  the 
proper  length,  may  now  be  securely  nailed  in  the 


106 


Concrete  Silos 


i  -E 


corners  of  these  two  boxes,  care  being  taken  that  the 

bevel  is  laid  in  the  right  direction.     The  rods,  which 

should  be  of  %- 

inch  iron  and  32 

inches    long, 

with  a  2-inch 

right    angle 

turned  at  each 

end,  can  now  be 

placed    in    the 

holes,    and    the 

narrow  strip 

which      was 

ripped    off    can 

be  cleated  back 

into    place.      A 

cleat  should  be 

used  at  each  rod 

and    should    be 

carefully  nailed 

with    4-penny 

nails.  The  2x4 's 

(H  in  the  plate), 

which      have 

been  spliced  together  to  a  length  of  exactly  30  feet, 

may  now  be  placed  in  the  form,  to  which  they  may  be 

fastened  by  means  of  boards  across  the  front.    These 

2x4 's  should  be  gauged  out  7  inches  from  board  A. 

The  door  form  is  now  ready  to  be  raised  into  place. 
When  it  has  been  raised  to  a  vertical  position,  it  should 
be  lifted  up  high  enough  so  that  the  8-inch  board  can 
be  let  down  on  the  inside  of  the  metal  lath  already  in 
place.  The  2x4's  should  rest  squarely  on  the  founda- 


ELEVATION 


r 

//  tf 

L 


DETAIL  OF  "A" 


SECTION 

Detail  of  Door  Frame. 


Concrete  Silos  107 

tion  and  against  the  lath  on  the  outside.  This  form 
must  now  be  carefully  plumbed  and  held  in  place  by 
short  braces  to  the  posts  and  planking  of  the  scaf- 
fold. All  braces  must  be  nailed  to  the  form  on  the 
inside  so  as  not  to  interfere  with  the  subsequent  plac- 
ing of  the  metal  lath  or  other  material. 

The  2x4  studding  should  be  prepared  for  raising 
by  being  spliced  together  to  a  length  exactly  of  30 
feet,  or  the  exact  height  of  the  silo  above  the  founda- 
tion. The  splice  may  be  made  by  lapping  the  ends  and 
nailing  them  together  with  three  16-penny  nails. 

The  plate  pieces,  which  have  been  sawed  out  in 
accordance  with  the  figures  given,  should  now  be 
hoisted  to  the  top  of  the  platform  of  the  scaffold.  Light 
gauges  should  be  prepared  for  use  in  space  the  2x4  's. 
It  is  a  good  plan  to  have  the  gauge  used  on  the  top 
platform  notched  at  one  end  so  that  it  may  be  used  in 
placing  the  inner  edge  of  the  2x4  2  inches  out  from 
the  inner  edge  of  the  plate. 

In  raising  the  studding  to  place,  begin  operations 
by  taking  one  of  the  plate  pieces  and  nailing  it  across 
the  top  of  the  door  form,  which  is  already  in  place,  the 
inside  edge  being  placed  2  inches  in  from  the  edge  of 
the  2x4 's.  A  single  8-penny  nail  driven  into  the  top 
of  each  2x4  is  sufficient  to  hold  this  in  place.  Now 
build  out  two  or  three  sections  of  the  plate,  breaking 
joints  and  doubling,  securely  nailing  together  the  two 
layers  with  6-penny  nails.  In  raising  the  2x4 's,  a  light 
line  is  a  great  convenience,  one  end  of  it  being  made 
fast  to  the  top  end  of  the  2x4's  with  a  timber  hitch,  so 
that  one  of  the  men  on  top  can  pull  the  stick  up,  while 
the  man  below  carries  the  foot  toward  the  scaffold 
and  sets  it  in  the  proper  place  on  the  foundation.  This 


108 


Concrete  Silos 


2x4  should  be  spaced  out  the  proper  distance  from  the 
2  x  4  of  the  door  form,  also  out  2  inches  from  the  inside 
edge  of  the 
plate;  a  16- 
penny  nail 
should  be 
driven  into  it 
through  the 
plate.  Raise 
the  next  2x4 
in  like  man- 
ner, building 
the  plate  on 
ahead  two  or 
three  sections 
at  a  time.  As 
soon  as  three 
or  four  2x4  's 
are  in  place, 
a  p  ie  c  e  of 
light  mate- 
rial, such  as 
ordinary 
weather- 
boarding, 
should  be 
bent  to  the 
form  of  a 
hoop  and 

nailed  to  each  2x4,  4  or  5  feet  above  the  foundation, 
with  a  4-penny  nail,  spacing  the  studding  with  the  same 
length  of  gauge  as  has  been  used  at  the  top. 

These   strips   of  weather   boarding  should  be   ex- 
tended as  the  2x4 's  are  set  until  circle  is  completed. 


Raising-  the  Door  Form. 


Concrete  Silos  109 

Since  the  door  form  is  carefully  plumbed  before 
one  begins  to  raise  the  2x4 's,  little  difficulty  is  experi- 
enced, as  a  rule,  in  having  the  whole  structure  stand 
perpendicular  when  the  circle  is  complete.  In  order 
to  have  the  segments  of  the  plate  unite  properly,  it 
will  probably  be  necessary  to  loosen  the  braces,  which 
were  nailed  on  top  before  the  circle  was  complete. 
After  the  parts  of  the  plate  have  been  brought  to- 
gether the  braces  should  again  be  nailed  in  place,  so 
that  the  scaffold  and  the  studding  may  be  securely 
tied  together.  A  second  hoop  should  be  placed  around 
the  silo  about  halfway  down  from  the  top;  and  if  the 
2x4 's  are  very  crooked  and  badly  out  of  line,  it  may 
be  necessary  to  place  still  another  hoop. 

The  pieces  of  gas-pipe,  which  have  previously  been 
cut  to  the  right  length,  should  now  be  placed  in  each 
door  box  and  wired  to  the  ends  of  the  rods  across  the 
door  form. 

The  24-gauge  expanded  metal  or  metal  lath  is  used 
in  the  construction  of  this  silo.  It  comes  in  bundles, 
each  bundle  usually  containing  nine  strips,  8  feet  long 
and  18  inches  wide.  A  bundle  of  this  size  contains  12 
square  yards  and  weighs  40^  pounds.  This  metal  lath 
is  tacked  to  the  inside  of  the  studding  with  double- 
pointed  tacks.  The  work  of  placing  it  should  begin  at 
the  top,  starting  at  the  door  post.  The  end  of  the 
first  strip  should  be  passed  through  the  opening  in  the 
side  of  the  door  box  and  bent  around  the  gas-pipe 
already  in  place.  Each  strip  of  lath  should  be  tacked  first 
in  the  middle ;  the  workman  should  go  from  that  place 
toward  the  end,  and  should,  as  the  tacks  are  driven, 
push  out  the  lath  so  that  it  naturally  takes  the  form  of 


110 


Concrete  Silos 


the  circle. 
The  end  of 
the  second 
piece  should 
be  lapped  at 
least  3  inches 
on  the  piece 
already 
placed.  So 
continue  un- 
til the  gas- 
pipe  on  the 
other  side  of 
the  door  is 
reached.  A 
good  pair  of 
snips  will  be 
necessary  in 
all  this  work, 
since  there  is 
considerab  1  e 
cutting  of 
lath.  Where 
the  ends  of 
lath  pass  the 
hooks  of  the 
rods  across 

the  door  it  will  be  necessary  to  split  the  end  back 
about  4  inches,  so  that  it  can  be  bent  around  the  gas- 
pipe  properly.  It  is  very  important  that  the  end  pass- 
ing around  the  gas-pipe  be  long  enough  to  encircle  it 
completely.  Two  workmen  are  needed  to  do  this  work 
to  good  advantage,  and  more  men  can  be  used  if  they 


Placing  Door  Frame  Reinforcement 


Concrete  Silos  111 

are  available.  The  different  rounds  of  the  lath  should 
lap  from  %  to  %  inch,  and  in  case  any  bagging  is  seen 
the  edges  must  be  wired  together  with  light  wire.  This 
will  prevent  a  great  deal  of  annoyance  to  the  plasterers 
in  placing  the  first  coat  of  plaster.  Whenever  it  be- 
comes necessary  to  splice  the  ends  between  studding, 
the  splices  must  be  carefully  wired  together.  When 
the  ends  are  spliced  on  the  studding  and  lapped  3 
inches,  this  wiring  is  not  necessary.  This  expanded 
metal  lath  has  a  right  and  a  wrong  side,  and  the  best 
results  are  secured  if  the  material  is  so  placed  that  the 
slant  of  the  mesh  is  upward  when  looked  at  from  the 
inside.  If,  when  the  bottom  is  reached,  the  lath  does 
not  come  out  even,  which  is  usually  the  case,  the  last 
round  may  be  left  full  width  in  case  there  is  enough 
lath  to  allow  this.  Care  taken  in  getting  this  lath 
smoothly  placed  and  carefully  wired  will  mean  the 
saving  of  money  later,  since  the  plasterers  can  make 
better  headway  where  this  work  has  been  properly 
done. 

Although  the  first  silos  of  this  type  contained  no 
other  reinforcement  than  the  metal  lath,  it  has  since 
been  thought  desirable  to  place  additional  horizontal 
reinforcement  in  the  form  of  strands  of  heavy  wire 
completely  encircling  the  silo.  These  wire  strands 
cannot  be  placed  until  all  of  the  inside  plastering  is 
done  and  the  studding  is  removed.  Provision  must  be 
made,  however,  for  their  attachment  to  the  vertical  re- 
inforcement in  the  door  post  before  any  mortar  is 
placed. 

Means  of  attachment  at  the  doors  can  be  most  easily 
provided  for  by  fastening  short  wire  loops  to  the  gas- 


112  Concrete  Silos 

pipe  in  the  door  post.  A  16-foot  silo,  30  feet  high, 
should  have  at  least  150  pounds  of  additional  wire 
reinforcement.  Since  the  pressure  is  much  greater  at 
the  bottom,  gradually  decreasing  toward  the  top  of  the 
silo,  a  larger  amount  of  the  wire  should  be  placed  in 
the  lower  part  of  the  wall.  The  table  shows  the  cor- 
rect spacing  of  the  wires  in  a  16-foot  silo  below.  The 
loops  attached  to  the  gas-pipe  to  which  these  wire 
strands  are  later  to  be  fastened  should  be  placed  in 
accordance  with  this  table,  and  may  be  put  in  place 
at  the  time  at  which  the  lath  is  being  tacked  to  the 
studding,  or  just  before  the  plastering  begins. 

Table  showing  proper  spacing  of  extra  wire  reinforcement  for 
silo  16  feet  in  diameter. 

Feet  from  top  Number  of  strands  of 

of  silo  No.  9  wire  required. 

0-  4 1  strand    for  every  24  inches. 

4-  8 1  strand     for  every  24  inches. 

8-12 1  strand    for  every  24  inches. 

12-16 1  strand    for  every  12  inches. 

16-20 2  strands  for  every  12  inches. 

20-24 2  strands  for  every     Sy2  inches. 

24-28 2  strands  for  every  6  %  inches. 

28-32 2  strands  for  every     5  inches. 

32-36 2  strands  for  every     4  inches. 

Silos  of  larger  size  will  require  one  additional 
strand  of  No.  9  wire  for  every  2  foot  increase  in 
diameter. 

After  the  metal  lath  and  the  wire  loops  are  in  place, 
the  thin  boards,  K,  should  be  nailed  in  place,  care  being 
taken  to  press  the  edge  as  tightly  as  possible  against 
the  lath,  since  this  box  is  to  be  later  filled  with  mor- 
tar. Plenty  of  nails  should  be  used  to  hold  these 
boards,  but  the  heads  should  be  left  slightly  out  so 
that  they  may  easily  be  drawn  later.  If  this  precau- 
tion is  not  taken,  some  difficulty  may  be  experienced 
in  removing  this  board  when  the  proper  time  comes. 


Concrete  Silos 


113 


Bolts  are  used  to  secure  the  plate  to  the  finished 
wall  of  the  silo,  and  these  must  be  in  place  before  the 
plastering  be- 
gins. Then 
%-inch  bolts 
10  inches 
long  will  be 
sufficient  for 
silos  not  ex- 
ceeding 1  6 
feet  in  diam- 
eter. Holes 
should  be 
bored  in  the 
plate  and 
should  be 
spaced  at  as 
nearly  equal 
distances 
apart  as  pos- 
s  i  b  1  e.  The 
bolts  should 
be  supplied 
with  washers 
and  should 


be  passed 
through  the 
plate  from 


Applying  the  First  Coat  of  Plaster  to  the   Inside. 


below,  and  the  nuts  put  on.  The  bolts  should  hang 
down  below  the  plate  just  inside  the  metal  lath  so  as 
to  be  covered  by  the  first  coat  of  plaster. 

It  is  almost  necessary  to  have  a  chute  on  the  silo, 
and  provision  should  be  made  for  attaching  this  chute 


114  Concrete  Silos 

by  placing  five  or  six  bolts  %  inch  by  4  inches  in  a 
perpendicular  line  3  or  4  inches  outside  of  the  door 
post.  These  bolts  may  be  passed  through  the  metal 
lath  with  the  nuts  on  the  outside.  As  the  plastering 
progresses,  care  should  be  taken  that  the  bolts  are 
made  to  project  perpendicularly  from  the  wall. 

The  mixture  for  the  scratch  coat  consists  of  1  part 
of  cement,  2%  parts  of  sand,  and  10  per  cent  as  much 
hydrated  lime  as  cement.  About  1  bushel  of  hair  to 
every  300  square  feet  of  surface  to  be  covered  must  be 
used  in  this  first  coat.  For  the  plastering  of  a  silo  16 
by  30  feet,  about  7  sacks  of  hydrated  lime  and  5  bush- 
els of  hair  will  be  required.  The  lime  should  be  soaked 
up  10  or  12  hours  before  it  is  to  be  used.  The  hair 
should  be  thoroughly  beaten  part  on  a  barn  floor,  and 
after  being  soaked  several  hours  should  be  carefully 
picked  to  pieces  and  worked  into  the  lime  putty  which 
has  been  prepared.  If  care  is  used,  the  hair  will  be 
thoroughly  mixed  with  the  lime  and  the  mixture  can 
be  added  to  each  batch  of  the  cement  mortar  as  it  is 
being  prepared  for  use.  It  will  take  about  1%  pailfuls 
to  each  2  bag  batch  of  mortar.  It  will  be  well  for  the 
plasterer  to  make  some  estimate  as  to  the  right  amount 
of  this  to  use  in  each  batch,  so  as  to  have  enough  to 
use  for  the  whole  scratch-coat.  This  coat  will  require 
about  13  two-bag  batches  of  mortar  for  16x30  foot 
silo. 

Two  good  plasterers  will  be  required,  and  four 
tenders,  two  to  measure  materials  and  mix  the  mortar, 
one  to  carry  and  elevate  it  to  the  proper  platform,  and 
the  fourth  to  receive  the  mortar  on  the  platform  and 
place  it  on  the  mortar-boards.  This  last  man  should 
do  all  the  moving  and  shifting  work,  so  that  the  plas- 
terers may  not  be  delayed  at  any  time. 


Concrete  Silos  115 

Sometime  during  the  process  of  applying  the 
scratch  coat,  the  space  under  the  door  should  have  been 
cased  up  inside  and  out  and  filled  with  mortar  mixed 
in  the  proportion  of  1  part  of  cement  to  2l/2  parts  of 
sand.  A  strip  of  wood  should  be  placed  across  the  bot- 
tom so  that  the  shoulder  which  is  cast  at  the  side  of 
the  doors  will  be  continued  across  the  bottom  of  the 
door. 

When  the  scratch  coat  is  all  on,  the  door  posts  are 
to  be  filled.  Since  the  8-inch  boards  forming  the  in- 
side of  the  form  have  a  tendency  to  spring  back  under 
the  weight  of  the  mortar,  some  provision  must  be  made 
to  hold  these  boards  rigidly  in  place.  This  can  easily 
be  accomplished  by  firmly  nailing  short  braces  to  the 
scaffold  plank  at  each  platform,  the  ends  being  braced 
solidly  against  the  back  of  the  form. 

If  this  work  can  be  completed  by  quitting  time  at 
night,  or  even  by  working  overtime,  the  thin  boards 
on  the  inside  can  be  removed  the  next  morning.  Con- 
siderable care  must  be  used  in  removing  these  boards, 
since  the  mortar  will  be  rather  green  and  easily  in- 
jured. The  placing  of  the  remaining  layers  of  plaster 
can  now  proceed  with  no  further  delay. 

The  mixture  for  the  second  layer  of  plaster  should 
consist  of  1  part  of  cement  to  2%  parts  of  sand,  and 
should  be  applied  in  three  coats,  giving  a  total  thick- 
ness, including  the  scratch-coat  of  at  least  1%  inches. 
In  applying  these  coats,  begin  at  the  top  and  work 
down,  one  coat  following  the  other  as  rapidly  as  pos- 
sible. An  old  broom  should  be  kept  on  the  scaffold, 
and  the  helper  should  rough  up  each  coat  as  soon  as  it 
has  wet  sufficiently,  so  that  succeeding  coats  will  not 
be  applied  to  the  glossy  surface  left  by  the  trowel.  It 


116  Concrete  Silos 

is  necessary  at  all  times  to  keep  water  upon  tlie  scaffold, 
since  many  times  the  work  will  dry  too  rapidly  and  it 
will  become  necessary  to  sprinkle  the  wall  before  the 
next  coat  of  plaster  is  applied. 

Before  applying  the  last  layer  of  plaster  to  the  in- 
side, the  inner  part  of  the  door  form  should  be  removed. 
With  this  form-  out  of  the  way,  the  finish  coat,  consist- 
ing of  equal  parts  of  cement  and  screened  sand,  may  be 
smoothly  applied  in  such  a  manner  as  to  leave  the  in- 
side surface  flush  with  the  face  of  the  door  post.  The 
use  of  water  is  very  important  during  the  application 
of  this  coat.  A  force  pump,  preferably  a  pump  run  by 
a  gasoline  engine  and  a  line  of  hose,  is  a  great  con- 
venience in  keeping  the  walls  thoroughly  wet. 

The  finish  coat  should  be  smoothed  up  neatly.  When 
it  has  sufficiently  set,  one  of  the  plasterers  should  mix 
up  a  wash  of  pure  cement  and  give  it  what  is  commonly 
called  a  "slush  coat."  It  should  be  the  aim  of  the 
plasterer  to  finish  this  coat  and  have  it  set  without  the 
appearance  of  checks  of  any  kind.  This  coat  should 
extend  down  upon  the  foundation  wall  to  the  bottom 
of  the  silo. 

Under  ordinary  conditions,  by  the  time  the  inside 
is  finished,  the  wall,  which  is  now  2  inches  thick,  has 
set  sufficiently  to  permit  the  removal  the  outside  stud- 
ding and  parts  of  the  door  form  still  in  place.  The 
inside  scaffold  should  be  removed  also;  one  should 
begin  at  the  top  and  pass  the  material  out  through  the 
door  opening.  The  first  step  in  taking  down  the  tem- 
porary studding  is  to  remove  all  the  hooping  material. 
When  the  foot  is  forced  loose,  the  2x4  may  be  pulled 
out  straight  from  the  silo  until  it  is  free  except  for  the 
nail  at  the  top.  By  pulling  down  on  the  stick,  one  may 
detach  it  from  this  nail  and  lay  it  on  the  ground.  It 


Concrete  Silos 


117 


is  a  good  plan  to  determine  the  number  of  legs  neces- 
sary for  the  outside  scaffold  before  removing  these 
studs.  By  leaving  two  of  them  at  each  point  where  the 
scaffold  legs 
are  to  stand, 
they  can  la- 
ter be  loos- 
ened from 
the  wall  and 
stood  out  at 
the  proper 
places,  thus 
saving  the  la- 
bor of  raising 
them  from 
the  ground 
again  while 
building  the 
outside  stag- 
ing. 

Before  the 
plastering  on 
the  outside  is 
begun  the  ex- 
tra wire  re- 
inforcement 
should  be  put 
in  place. 


Pouring  the  Door  Posts. 


This   wire   is 
to     be     a  t- 

tached  to  the  wire  loops  which  now  lie  flat  on  the  out- 
side of  the  wall.  The  number  of  strands  of  wire  to  be 
placed  at  each  loop  is  given  in  the  table.  These  hoops 


118 


Concrete  Silos 


of  wire  should  be  passed  around  the  silo  and  attached 
to  the  loops  on  the  opposite  side.  Continue  this  process 
until  all  hoops  have  bands  of  wires  attached  to  them. 

The  lumber 
used  for  the  inside 
scaffold  is  to  be 
used  in  building  a 
scaffold  on  the 
outside,  the  30- 
foot  2x4 's  left  in 
place  being  used 
for  the  legs  of  the 
scaffold.  Care 
must  be  taken  that 
the  inside  legs  and 
the  plank  runway 
of  this  scaffold  are 
at  such  a  distance 
from  the  wall  of 
the  silo  as  will  be 
convenient  for  the. 
plasterers  to  work. 

The  outside 
layer  of  plaster 
should  be  at  least 
1  inch  in  thickness 
and  should  be  ap- 
plied in  2  coats, 
using  one  part  of 
cement  to  2% 
parts  of  sand.  The  use  of  the  darby  on  the  last  out- 
side coat  will  add  to  the  appearance  of  the  silo.  A 
float  finish  gives  a  pleasing  appearance  to  the  outside. 


HORIZONTAL    SLCTIQN  CF  WALL  AT  DOOR,. 


Concrete  Silos  119 

The  use  of  a  wash  coat  of  pure  cement  as  a  final  finish 
will  also  greatly  improve  looks  of  the  silo.  The  walls 
should  be  thoroughly  wet  before  this  coat  is  applied. 

The  finished  silo  should  be  wet  thoroughly  once 
daily  for  at  least  a  week  after  the  job  is  complete.  The 
use  of  water  is  a  very  important  factor  in  the  securing 
of  a  good  concrete  job  built  above  ground,  since  the 
constant  tendency  is  for  the  material  to  dry  before 
proper  setting  can  take  place. 

The  same  type  of  doors  described  for  use  in  the 
solid-wall  silo  with  continuous  door  opening  can  be 
used  in  this  silo. 

In  order  to  provide  against  freezing  of  silage  in  se- 
verely cold  climates,  a  double-wall  metal-lath  silo  has 
been  developed,  as  illustrated  herewith.  The  sill 
is  made  of  2-foot  lengths  of  2x4 's  imbedded  in 
the  concrete  foundation.  The  studding 
are  2x4 's  spliced  to  the  proper  lengths 
as  outlined  for  the  temporary 
studding  used  in  construct- 
ing the  single  wall  metal 
lath  silo.  T  h  e  s 


Roof    for    Metal    Lath    Silo. 


studding  are  set  on  the  sill  and  are  toe-nailed  to  it. 
On  each  side  of  the  door  opening  are  set  two  2x4 's 
spiked  together  to  form  4x4 's  for  the  door  frame. 


120 


Concrete  Silos 


These  are  bolted  together  across  the  opening  by  %  inch 
rods.  A  jamb  for  the  doors  to  fit  against  is  formed  by 
sawing  a  2x4  as  outlined  previously  in  this  chapter. 
The  plate  at  the  top  of  the  silo  is  made  the  same  as  for 
a  single  wall  silo.  After  the  frame  has  been  completed 
metal  lath  is  stapled  to  both  the  inside  and  outside  of 


Concrete    Silo    for    Walker    Bros.,    Walkerville,    Ont. 

Note  the  attractive  appearance  of  permanent  Concrete  Silo  (at 
left)  compared  with  wood  silo  (at  right)  which  is  already  showing 
signs  of  deterioration. 


00 


132 
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132 


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20  Sq.  Yds. 
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"AS* 

Wire  reinforce 
ent  required 


156  Sq.  Yds. 
of  Lath 
276  Lin.  Ft 
No.  8  Wire 


38  q  ds. 
ofLath 
58  Lin.  Ft 
No.  8  Wire 


*Jl4 


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ment  requ 


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ment  req 


i* 


114  Sq. 
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racnt  required 


- 


74  q.  Yds. 
of  Lath 
20  Lin.  Ft 
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Sq.  Yds. 
of  Lath 
30  Lin.  Ft 
o.  8  Wire 


£     gS5  2     S55 


£•$*-.£  Z-S^t 


£^ 


50  Sq. 
of  Lath 
60  Lin.  Ft 
No.  8  Wire 


180  Sq.  Yds. 
of  Lath 
877  Lin.  Ft 
No.  8  Wire 


2    8* 


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S 


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Ft 
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Lin. 
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252  ds. 
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3360  Lin.  Ft. 
No.  8  Wire 


.  ds. 
of  Lath 
950  Lin.  Ft 
No.  8  Wire 


228  q.  ds. 
of  Lath 
2720  Lin.  Ft 
No.  8  Wire 


98  Sq.  Yds. 
of  Lath 
560  Lin.  Ft 
No.  8  Wire 


8 


332  Sq.  Y 
ofLath 
6708  Lin.  Ft 
No.  8  Wire 


336  Sq.  Y 
ofLath 
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122 


Concrete  Silos 


the  studding,  placed  with  the  long  dimension  around 
the  silo. 

In  estimating  the  quantity  of  metal  lath  required  for 
a  double  wall  silo,  the  table  given  in  this  chapter  can 
be  used,  remembering  to  use  just  twice  the  amounts. 

Silos  are  also  made  from  the  various  special  pat- 
ented types  of  metal  lath  now  on  the  market.  With 
some  of  these  it  is  found  to  be  possible  to  erect  the 
silo  without  the  use  of  the  temporary  studding  previ- 
ously described. 

One  such  is  the  product  known  as  Hy-Rib,  made  by 
the  Trussed  Concrete  Steel  Company,  Youngstown,  0. 
This  is  a  herringbone  metal  lath  with  deep  corrugations 
or  ribs  pressed  in  it  at  regular  intervals,  these  giving 


Hy-Rib  Acts  As  a  Form  and  Reinforcement  for  the  Concrete. 
Note  the  temporary  wood  frame  for  metal  sheets.  If  the 
wood  frame-work  is  to  be  removed  the  sheets  must  be  wired 
together.  If  2x4-inch  rafters  are  to  be  left  the  metal  may  be 
nailed  lightly  to  them  and  the  cross  boards  only  removed. 
This  is  undoubtedly  the  quickest  and  cheapest  method. 


Concrete  Silos  123 

it  strength  and  stability.  The  type  usually  recom- 
mended for  silos  is  made  from  24  gauge  metal,  has  the 
ribs  4  inches  apart  and  15/16  inch  high,  and  comes  in 
sheets  24  inches  wide  and  10  and  12  feet  long.  For 
silo  work  these  sheets  are  curved  at  the  mill  to  the  de- 
sired radius.  These  sheets  can  either  extend  down  into 
the  foundation,  as  shown  in  the  illustration,  or  can 
begin  at  the  top  of  the  foundation.  In  the  latter  case 
dowel  pins  are  set  in  the  foundation,  and  allowed  to 
extend  several  inches  above  it,  for  attaching  the  first 
ring  of  Hy-Rib.  The  construction  as  shown  in  the  illus- 
tration is  recommended,  however,  carrying  the  metal 
down  to  the  footings. 

It  will  be  noted  also  that  rib  bars  are  used  to  give 
stability  to  the  walls  while  being  plastered.  These  are 
%  inch  ribs,  wired  to  the  metal  sheets,  and  left  in  as 
a  permanent  part  of  the  silo.  Plaster  is  applied  on  both 
sides  of  the  metal  to  a  total  thickness  of  3  or  3%  inches. 

In  this  type  of  construction  the  builder  may  erect 
the  metal  to  a  height  of  30  feet  before  beginning  to 
plaster,  or  he  may  erect  it  in  sections  and  plaster,  as 
desired.  After  any  plastering  is  done,  however,  it  will 
require  at  least  a  half  day  to  harden  before  any  more 
metal  is  placed. 

The  roof  of  a  Hy-Rib  concrete  silo  may  be  of  a  cone 
shape,  a  dome  shape,  or  an  octagonal  hip,  which  are  all 
constructed  of  Hy-Rib  covered  with  2  inches  of  con- 
crete, back-plastered  underneath.  The  chute  may  be 
built  in  connection  with  the  side  walls  using  Hy-Rib  of 
any  desired  size,  thereby  making  the  chute,  side  walls 
and  roof  of  silo  one  complete  unit  with  the  foundation. 

A  silo  similar  to  the  above  is  made  by  the  use  of 
Trusridge  expanded  metal,  made  by  the  Edwards 
Metal  Structures  Company,  Kansas  City,  Mo.  In  this 


124  Concrete  Silos 

case,  however,  %-inch  pipe  is  used  for  studs,  to  which 
the  metal  is  wired.  The  pipes  are  furnished  in  10  and 
12-foot  lengths,  threaded  for  unions,  and  are  held  in 
place  by  a  ring  of  angle  iron  which  has  holes  punched 
in  it  for  the  pipes.  This  ring  holds  the  pipes  to  a  true 
circle. 


CHAPTER  XV 
THE  CONCRETE  STAVE  SILO 

The  concrete  stave  silo  is  patterned  after  the  wood 
stave  silo,  and  has  been  developed  in  an  attempt  to 
introduce  some  of  the  elements  of  ease  of  erection  and 
low  cost  of  the  wood  silo,  combining  with  them  the 
features  so  desirable  in  concrete. 

These  silos  are  built  up  of  members  resembling 
staves,  and  erected  and  held  together  in  the  same 
manner.  It  would  manifestly  be  impossible,  however, 
to  make  them  in  such  lengths  as  are  handled  in  wood, 
so  that  the  length  of  the  concrete  staves  is  limited 
usually  to  28  or  30  inches.  They  may  be  either  made 
on  the  job,  or  shop-cast  and  moved  to  the  place  of  erec- 
tion. In  this  latter  case  they  can  usually  be  cured 
under  better  conditions  and  there  will  not  be  the  dan- 
ger of  hurrying  them  into  the  structure  before  the 
proper  curing  has  taken  place.  These  staves  are  usu- 
ally poured  of  slush  concrete  in  multiple  steel  molds. 

The  staves  are  generally  made  in  a  width  of  about 
10  inches  and  are  cast  flat.  The  usual  thickness  is 
about  2%  inches.  All  types  have  some  method  of  giv- 
ing the  staves  a  vertical  joint,  and  some  of  them  also 
provide  a  horizontal  joint  where  the  ends  of  the  staves 
come  together.  The  joints  are  filled  with  mortar.  To 
still  further  safeguard  the  structure  against  air  and 
moisture,  the  inside  may  be  plastered  or  given  a  wash 
coat  of  cement. 

In  constructing  the  silo  the  staves  are  assembled 
with  staggered  joints,  the  first  row  of  staves  consist- 
ing of  alternate  full  length  and  half  length  staves. 

(125) 


126 


Concrete  Silos 


These  silos  are 
held  together  by  out- 
side hoops,  as  is  the 
case  with  wood 
staves,  the  hoops  be- 
ing placed  closer  to- 
gether at  the  bottom 
to  provide  for  the 
greater  strain,  the 
spacing  being  gradu- 
ally increased  as  the 
top  is  approached. 

Some  of  the  com- 
mercial stave  silo 
systems  now  on  the 
market  are  described 
in  the  following 
pages. 

Many  of  these 
silos  have  been  built 
on  the  foundations 
of  old  wood  stave 
silos  and  are  giving 
excellent  satisfac- 
tion, a  point  which 
is  worth  while  re- 
membering in  pro- 
moting the  sale  of 
these  silos.  The 
foundation  for  the 
stave  silo  is  made 
the  same  as  for  other 
types. 


Perfection  Stave  Silo  on  State  Fair 
Grounds  at  Des  Moines,  la.  Diameter 
14  feet  4  inches ;  height  44  feet  4 
inches  ;  capacity  194  tons. 


Concrete  Silos 


127 


Perfection  Concrete  Stave  Silo.  This  system  is 
controlled  by  the  Perfection  Concrete  Stave  Silo  Com- 
pany, Des  Moines,  Iowa,  and  the  outfit  with  which 
the  staves  are  made  is  sold  outright  to  manufacturers. 
These  staves  can  be  used  for  structures  from  10  to 
36  feet  in  diameter  and  up  to  60  feet  high. 

The  staves  are  28  inches  long,  10  inches  wide,  2% 
inches  in  thickness,  and  are  made  in  steel  forms  with 
a  wet  mix,  waterproofed  and  made  impervious  by  the 
addition  of  10  per  cent  of  the  weight  of  cement  in 
hydrated  lime.  The  staves  are  made  concave  on  the 
edges  and  on  the  ends,  and  when  they  are  assembled 
in  the  silo  the  space  which  is  thus  formed  is  filled  with 
mortar. 

The  company  also  manufactures  for  use  on  its  silos 
a  malleable  iron  door  frame  and  an  all-steel  door  with 
steel  ladder  combina- 
tion. The  door  sys- 
tem is  continuous 
from  the  foundation 
to  roof,  the  frame 
occupying  a  space  of 
only  4  inches  between 
doors.  Each  door 
opening  is  23x25  in. 

In  Constructing  the 

silo,  one  of  the  malle- 

able  iron  door  frames 

is  placed  upon  a  circular  concrete  foundation,  and  half 

staves   (that  is,  14  inches  in  length  by  10  inches  in 

width  by  2%  inches  in  thickness),  are  plaped  on  the 

foundation,    in    the    channel    on    either    side    of    the 

malleable  iron  door  frame;  then  a  full  length  stave  is 


The    Perfec  Silo    Steel    Door    in 

steel  ladder  sys" 


128  Concrete  Silos 

stood  up  by  the  side  of  each  half  stave,  and  the  circle 
is  completed  by  alternate  half  and  whole  staves. 
Thereafter,  whole  staves  are  used  until  the  top  of  the 
silo  is  reached,  when  half  staves  are  used  to  fill  out 
the  top,  alternately  between  the  full  staves. 

On  completion  of  the  first  circle,  two  bands  are 
placed  around  the  circle,  one  2  inches  above  the  foun- 
dation and  another  half  band  is  placed  14  inches  above 
the  foundation,  and  the  end  of  the  half  band  is  placed 
in  the  lugs  on  either  side  of  the  door  and  turned  up 
even  with  the  end  of  the  rod. 

As  each  course  is  erected  and  put  into  place,  the 
concavity  between  staves  is  filled  with  mortar,  con- 
sisting of  1  part  cement,  to  3  parts  of  screened  sand, 
and  the  ends  of  the  staves  as  they  meet  are  also  filled 
with  mortar,  so  that  when  the  silo  is  completed  every 
joint  is  filled,  thus  preventing  any  escape  of  the  silage 
juices  or  admission  of  air  into  the  silo. 

Suitable  collapsible  staging  is  erected  on  the  in- 
side of  the  silo  as  the  walls  are  being  extended  upward. 

As  soon  as  the  silo  walls  are  completed,  a  water- 
proofing composition  is  placed  upon  the  inside  wall 
by  brush  applications. 

In  this  system  the  contractor  is  supplied  with  steel 
molds  sufficient  to  cast  200  staves  or  more  a  day.  The 
supposition  is  that  the  contractor  will  haul  his  molds 
to  the  farm,  or  the  place  where  the  silo  is  to  be  "built, 
and  that  the  owner  will  provide  the  materials  ready 
for  working.  The  contractor  will  then  send  two  ex- 
perienced men  to  cast  the  staves.  The  manufacturers 
state  that  it  will  require  900  staves  to  build  a,  silo  16 
feet  in  diameter  by  35  feet  high,  holding  150  tons  of 


Concrete  Silos 


129 


silage.  The  two  men  it  is  stated  will  cast  these  in  4% 
days.  They  are  then  left  4  or  5  days  to  cure  before 
being  erected. 

Playford  Cement  Stave  Silo.  This  system  is  con- 
trolled by  the  Cement  Stave  Silo  Company,  Des  Moines, 
Iowa.  These  staves  are  made  30  inches  long,  10  inches 
wide  and  2%  inches  thick.  One  edge  is  concave  and 
the  other  convex,  so  that  the  staves  fit  closely  to- 
gether, no  matter  what  the  radius  of  the  silo  and  the 
consequent  curvature  of  the  walls.  In  building  a  Play- 


Playford   Silo   With   Door   Spreaders 


Chute. 


ford  Silo  the  first  row  consists  of  alternate  full  and 
half  length  staves;  thus  the  joints  are  broken  the 
entire  way  up,  and  the  last  row  finished  with  alter- 
nate full  and  half  lengths.  These  silos  when  erected 
are  held  together  with  hoops  of  round  steel  joined 
with  patent  lugs.  These  hoops  are  put  on  as  the  silo 


130 


Concrete  Silos 


goes  up,  so  that  the  structure  is  held  perfectly  rigid 
at  every  stage  of  construction.  Alternate  hoops  en- 
tirely encircle  the  silo,  when  the  intermediate  hoops 
fasten  to  door  spreaders,  these  passing  around  the 


The  Playford  Cement  Stave 

door  openings  and  leaving  them  unobstructed.  A 
combination  sectional  ladder  and  chute  is  also  pro- 
vided. After  erection  the  silo  is  treated  with  a  special 
waterproof  filler  coating  on  the  inside. 

Reinforced  Stave  Silo.     This  stave,  which  is  con- 
trolled by  the  Playford   Manufacturing   Company   of 


FOR  Poirmwa 


Reinforced  Stave   Silo 


Elgin,  Illinois,  carries  an  outside  vertical  rib  on  one 
edge  through  which  passes  a  a/4-inch  twisted  reinforc- 
ing bar.  The  thickness  through  the  stave  proper  is 


Playford    Cement    Stave    Silo. 
(131) 


132 


Concrete  Silos 


21/4  inches  while  the  thickness  through  the  rib  is  4% 
inches.  The  stave  is  12  inches  wide  and  30  inches 
long. 

Each  stave  carries  a  lug  on  top  with  a  correspond- 
ing recess  in  the  bottom,  forming  a  lock  for  the  lateral 
joints.  A  concave  and  convex  joint  on  the  sides  of 


Method  of  Assembling  Reinforced  Silo   Staves 

the  slabs  is  so  designed  that  space  is  allowed  for 
pointing  up  on  the  outside  after  the  silo  is  erected. 
The  silo  is  also  given  a  cement  wash  on  the  inside,  giv- 
ing it  a  double  seal. 

The  ribs  on  the  outside  of  the  staves  carry  prop- 
erly spaced   depressions   for  receiving  the  hoops,   so 


Reinforced   Stave   Silo 
(133) 


134  Concrete  Silos 

that  the  latter  cannot  slip  out  of  place.  The  hoops, 
being  held  out  from  the  face  of  the  silo  by  the  ribs, 
form  a  convenient  ladder  for  climbing  up  the  silo  at 
any  point. 

A  continuous  door  system  is  provided  for,  special 
staves  being  made  for  the  door  opening  which  carry 
an  offset  against  which  the  door  can  rest  and  also 
having  recesses  into  which  a  casting  can  be  slipped 
as  a  dividing  plate  between  doors.  This  casting  is 
held  firmly  in  place  automatically  when  both  the  up- 
per and  lower  staves  are  in  position.  The  doors  are 
of  wood,  held  in  place  by  latches  which  are  turned 
over  the  flange  of  the  castings  above  and  below. 

A  galvanized  iron  roof  is  usually  put  on,  with  a 
chute  either  of  that  material  or  built  up  of  the  staves 
themselves. 

The  staves  iare  poured  of  a  slush  mixture  in  in- 
dividual molds  of  sheet  steel  and  are  allowed  to  re- 
main in  the  molds  for  24  hours. 

Interlocking  Cement  Stave  Silo.  This  system,  con- 
trolled by  the  Interlocking  Cement  Stave  Silo  Com- 
pany, Des  Moines,  Iowa,  has  as  its  most  noticeable 
feature  a  bevel  on  the  ends  of  each  stave.  This  irregu- 
lar form  of  joint  makes  it  possible  for  a  single  band 
passing  around  the  joint  to  hold  the  ends  of  all  staves 
— both  those  ajbove  and  those  below.  Concave  and 
convex  edges  also  provide  an  additional  interlock. 

The  staves  are  28  inches  long,  10  inches  wide  and 
2%  inches  thick.  The  company  makes  two  types  of 
equipment  for  the  manufacturing  of  these  staves,  one  of 
them  adapted  to  the  manufacture  of  small  and  inter- 
mittent lots  of  staves,  and  tKe  other  a  larger  outfit  for 
making  larger  quantities.  Both  make  identically  the 
same  design  of  product. 


Concrete  Silos 


135 


The  first  mentioned  is  a  hand  mold,  open  at  top 
and  bottom  and  designed  to  rest  on  a  pallet  and  be 
withdrawn  after  the  concrete  is 
tamped  in  and  struck  off;  the 
other  is  a  machine  somewhat 
similar  to  a  concrete  block  or 
brick  machine,  in  which  the 
operations  are  done  more  rap- 
idly by  mechanical  means. 
Both  outfits  are  provided  with 
means  for  making  fractional 
staves  as  needed. 

A  mold  for  casting  a  sec- 
tional concrete  door  frame  is 
also  a  part  of  each  outfit.  This 
door  frame  is  the  same  height 
as  a  stave,  28  inches,  and  40 
inches  wide,  taking  the  place 
of  four  staves;  it  also  is  pro- 
vided with  one  concave  and 
one  convex  edge  to  fit  into 
adjoining  staves.  It  thus  can 
be  used  continuously  or  inter- 
mittently as  desired.  The  door 
frame  has  an  opening  of  28x20  inches,  with  an  offset 
to  accommodate  a  wood  door. 

Swan  Stave  System.  This  design  of  stave  was  orig- 
inated by  the  Swan  Concrete  Stave  Silo  Company, 
Cassopolis,  Michigan.  It  is  a  dry  tamp  stave  made  in 
a  simple  form  on  wood  pallets,  the  pallets  being  curved 
to  the  radius  of  the  silo.  The  staves  are  dovetailed 
on  the  ends  and  each  stave  also  has  a  tongue  on  one 
side  and  top  and  a  groove  on  the  other  side  and  the 


Interlocking  Cement 
Staves. 


136 


Concrete  Silos 


bottom.  The  staves 
are  30  inches  long, 
10%  inches  wide, 
and  2l/2  inches  thick. 
Supreme  Silo.  The 
patent  on  this  silo  is 
held  by  J.  A.  Brod- 
erick,  of  Marshall- 
town,  Iowa.  It  is 
built  with  either  a 
single  or  double  Swan  stave  Sil° 

wall,  the  former  being  recommended  for  warmer  cli- 
mates and  the  latter  for  colder.     The  distinctive  fea- 


A    Plant    Manufacturing-    Swan    Staves 

ture  of  this  system  is  a  concrete  band  or  rib  which  is 
cast  around  the  silo  after  the  slabs  are  laid  up,  one  of 
these  being  placed  at  each  joint  and  serving  to  cover 
the  reinforcing  as  well  as  cover  the  joint  between  the 


Concrete  Silos  137 

ends  of  the  slabs.  In  order  to  accomplish  this  result 
the  slabs  are  laid  up  with  even  lateral  joints  and  stag- 
gered vertical  joints,  just  the  opposite  of  the  general 
custom  in  stave  construction.  The  concrete  ribs,  being 
carried  completely  around  the  structure,  also  form  sills 
and  lintels  for  the  door  frames  where  they  cross  the 
door  openings. 

Everlasting  Silo  Staves.  W.  W.  Rohrer  &  Son  of 
Orrville,  Ohio,  have  a  system  of  silo  stave  manufacture 
to  make  staves  24  inches  long,  10  inches  wide  and  3 
inches  thick.  One  vertical  edge  of  each  stave  is  con- 
cave and  the  other  convex,  making  a  perfect  joint. 
Half  length  staves  are  used  in  starting  the  silo,  so  that 
joints  are  broken  all  the  way  up.  The  staves  are  held 
together  with  %-inch  iron  rods  with  patent  knuckles. 
As  each  row  of  staves  is  placed  in  position  the  hoop  is 
placed  around  and  drawn  up  tight,  each  band  passing 
around  the  middle  of  half  the  staves  and  the  ends  of 
the  intermediate  ones. 

It  is  claimed  that  a  special  mixture  is  used  in  mak- 
ing these  staves,  rendering  them  impervious  to  mois- 
ture and  also  acid  probf. 

Panel  Silos.  These  can  perhaps  best  be  included 
under  the  general  heading  of  stave  silos,  although  in 
this  case  the  units  run  horizontally  instead  of  ver- 
tically. This  system  is  controlled  by  the  Concrete 
Panel  Silo  Company  of  Kansas  City,  Missouri.  It  con- 
sists of  poured  concrete  columns  alternating  with  pre- 
cast concrete  slabs.  The  slabs  are  10  inches  high,  24 
inches  long,  and  3  inches  thick. 

In  erecting  the  silo,  the  slabs  are  first  laid  up  to  a 
convenient  height,  with  reinforcing  rods  in  the  hori- 


138  Concrete  Silos 

zontal  mortar  joints  between  courses.  The  ends  of  the 
slabs  have  an  outside  bevel,  leaving  a  considerable  out- 
side opening  between  the  ends.  Against  this  opening 
a  steel  form  is  erected  and  poured  full  of  concrete, 
thus  closing  up  the  joint,  and  making  a  column  to 
add  to  the  stability  of  the  structure.  This  column  is 
reinforced  with  a  %-inch  vertical  rod.  Intermittent 


Diamond    Stave    Silo 

door  openings  are  made  by  omitting  three  panels  at 
suitable  intervals  in  one  tier. 

Diamond  Concrete  Stave  Silo.  This  system  is  sold 
by  the  Diamond  Concrete  Stave  Silo  Company,  Kan- 
sas City,  Mo.  These  staves  are  diamond  shaped,  inter- 
locking with  tongue  and  groove,  and  held  together 
by  either  round  rods  or  bands.  They  are  30  inches 


Concrete  Silos  139 

long,  11%  inches  wide  at  the  middle  and  6  inches  at 
the  ends.  A  notable  feature  of  the  staves  is  that  they 
are  thicker  in  the  center  than  at  the  edges,  the  center 
thickness  being  3  inches  and  at  the  edges  2%  inches. 
This  provision  is  made  to  give  the  finished  silo  an 
outside  curvature,  allowing  the  bands  to  fit  more 
snugly  instead  of  resting  only  on  the  edges  of  the 
staves. 


CHAPTER  XVI 
CONCKETE  BLOCK  SILOS 

The  concrete  block  silo,  if  well  made,  has  at  least 
two  advantages  to  recommend  it:  It  is  usually  made 
of  hollow  blocks,  thus  providing  an  air  space  in  the 
wall  which  will  help  to  insulate  the  contents  against 
frost  and  moisture;  and  if  some  care  is  taken  in  the 
design  and  construction,  it  can  be  given  a  more  decora- 
tive appearance  than  is  customary  with  the  general 
run  of  farm  structures. 

On  the  other  hand  there  are  certain  precautions 
which  must  be  taken  in  putting  up  this  kind  of  a  silo. 
Most  of  the  silo  block  systems  provide  for  a  dry  or 
semi-dry  tamp  block.  With  such  a  block  it  is  of  the 
utmost  importance  that  the  materials  be  properly  se- 
lected, graded  and  mixed,  and  the  manufacturing  and 
curing  be  done  in  the  most  approved  manner,  else  the 
block  will  not  have  sufficient  density  to  make  it  mois- 
ture proof.  It  is  worth  while,  therefore,  to  urge  upon 
block  manufacturers  the  extreme  importance  of  put- 
ting the  best  quality  of  materials  and  workmanship 
into  silo  blocks ;  and  also  to  urge  upon  owners  that 
they  give  careful  attention  to  the  blocks  they  are  get- 
ting, contracting  for  them  only  with  manufacturers 
who  have  the  best  reputation. 

For  the  manufacture  of  silo  blocks  a  clean,  well 
graded  sand  should  be  used,  and  the  mixture  should 
be  1  part  cement  to  3  parts  sand.  The  mix  should 
be  made  as  wet  as  the  molds  will  lallow,  and  should 
preferably  be  cured  by  steam,  taking  care  that  the 

(140) 


Concrete  Silos 


141 


blocks  are  not  allowed  to  dry  out  before  having  the 
steam  turned  on  them.  Additional  waterproofness  can 
be  secured,  if  necessary,  by  the  addition  of  some  good 
waterproofing  substance  to  the  concrete  when  it  is 
made,  or  by  the  application  of  an  inside  or  outside 


Two  Decorative  Silos  of  Ideal  Blocks  on  the  Barber  Estate, 
Barberton,  Ohio 

coating,  or  both.  A  coat  of  cement  plaster  on  the 
inside  will  be  conducive  to  this  end,  and  will  also  have 
the  advantage  of  giving  the  silo  a  smooth  wall. 

In  starting  the   construction  of  a  concrete  block 
silo,  the  excavation,  floor  and  footings  will  be  the  same 


142  Concrete  Silos 

as  for  a  monolithic  silo.  In  starting  the  walls,  however, 
some  readjustment  of  the  radius  may  be  necessary  in 
order  to  accommodate  the  construction  to  the  size  of 
units  available.  The  length  of  silo  blocks  is  not  usu- 
ally changed  for  the  various  diameters,  so  that  in  order 
to  make  it  possible  to  use  only  whole  and  half  blocks, 
or  such  fractions  as  the  machine  will  make,  and  thus 
avoid  cutting,  it  will  be  well  to  lay  out  a  test  circle 
after  the  footings  are  in  and  see  how  closely  the  blocks 
conform  to  the  desired  size.  The  circle  can  then  be 
made  slightly  larger  or  smaller  to  accommodate  them. 

The  cement  mortar  should  consist  of  1  sack  of 
Portland  cement  to  2  cubic  feet  of  clean  sand,  with 
the  possible  addition  of  a  small  quantity  of  hydrated 
lime  (not  over  ten  per  cent),  to  make  it  easier  to  work. 
Before  laying  up  the  blocks,  see  that  they  are  thor- 
oughly soaked  which  will  prevent  them  from  draw- 
ing moisture  from  the  mortar.  No  more  mortar  should 
be  mixed  at  one  time  than  can  be  used  up  within  30 
minutes  after  first  moistening. 

Most  blocks  now  made  for  silo  work  have  some 
provision  for  continuous  reinforcement;  but  if  such 
provision  is  not  made,  reinforcing  wire  must  be  used 
between  the  courses  of  blocks.  A  table  herewith  gives 
the  -amounts  of  reinforcing  necessary  for  block  silos. 

The  doors  in  a  block  silo  are  installed  similarly  to 
those  in  silos  of  other  types.  For  intermittent  doors, 
frames  6  inches  wide  of  2-inch  lumber  are  placed  at 
proper  intervals  in  the  8-inch  wall.  This  leaves  a  2- 
inch  recess  on  the  inner  surface  of  the  wall  in  which 
will  set  the  wooden  door.  Vertical  steel  rods  are  set 
in  mortar  in  airtight  spaces  of  the  block  next  each  side 
of  the  doors,  and  the  horizontal  reinforcing  hooked 
around  them.  Sufficient  extra  rods  are  placed  across 


Concrete  Silos 


143 


Block  Silo  at  Atlanta,  111. 


the  top  and  bottom  of  the  door  to  equal  the  horizontal 
rods  which  are  cut  out  by  the  door  opening. 

For  a  continuous  door,  a  vertical  concrete  frame  is 
sometimes  cast  on  each  side  of  the  door  opening.    In 


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Concrete  Silos  145 

this  frame  are  embedded  the  vertical  rods,  to  which 
all  the  horizontal  rods  are  hooked,  in  a  manner  simi- 
lar to  that  described  for  monolithic  silos.  At  other 
times  angle  irons  or  U-bars  are  used  for  frames,  or 
special  iron  shapes,  with  offsets  for  doors  are  used. 

A  wooden  or  metal  chute  can  be  fastened  to  the 
walls  or  one  can  be  built  of  blocks  at  the  same  time  as 
the  walls. 

The  roof  of  a  block  silo  can  be  made  either  of  wood 
or  of  concrete.  When  of  concrete,  the  method  of  pro- 
cedure is  the  same  as  that  specified  for  solid  wall  silos, 
except  that  the  temporary  roof  rafters  rest  on  the 
wall,  and  the  eaves  'are  formed  'by  a  special  block 
which  gives  the  necessary  overhang. 

Below  are  given  brief  descriptions  of  a  number  of 
the  systems  of  silo  block  construction  now  available. 

Hurst  System.  This  system  is  marketed  by  the 
Hurst  Silo  Equipment  Company  of  Chicago.  The 
unit  of  construction  is  a  solid  block  231/2  inches  long, 
11%  inches  high,  and  4  inches  thick.  Each  block  is 
reinforced  with  two  %-inch  round  rods,  the  ends  of 
these  rods  projecting  into  recesses  at  the  end  of  each 
block  and  being  bent  into  a  hook  to  receive  a  steel 
link.  When  the  blocks  are  laid  up  in  the  wall,  the 
ends  of  rods  in  adjoining  blocks  are  thus  brought  to- 
gether, and  after  the  link  is  slipped  over  them  the  ends 
are  bent  back  by  means  of  a  tool  supplied  for  the  pur- 
pose. This  makes  the  reinforcing  continuous  around 
the  structure,  and  the  process  of  bending  up  the  rods 
serves  to  bring  the  steel  into  tension  and  thus  resist 
the  pressure  of  the  silage  when  the  silo  is  filled.  The 
recesses  which  hold  the  links  are  afterwards  filled  with 
mortar,  as  well  as  the  V-shaped  joint  between  the 
blocks  on  their  inside  surface. 


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(146) 


Concrete  Silos 


147 


These  blocks  are  cast  in  steel  molds,  each  mold 
making  ten  blocks  at  one  operation.  A  reference  to 
the  illustration  here  shown  will  give  a  very  good  idea 
of  the  assembling  of  the  mold.  Each  mold  consists  of 
two  sides,  two  sets  of  division  plates,  clamps  for  lock- 
ing molds,  and  core  covers.  The  sides  of  the  mold  are 
of  pressed  steel,  fitted  with  hollow  pressed  steel  cores, 


Method  of  Laying  up  Hurst  Blocks 

which  form  the  recesses  at  the  ends  of  the  blocks  and 
which  also  hold  the  reinforcing  rods  in  place  while  the 
blocks  are  poured.    The  division  plates  are  of  %-inch 
rolled  steel,  24  inches  long  and  the  height  of  the  block. 
These   division  plates  are  curved  to   conform  to  the 
diameter  of  the   silo   and  can  be   furnished  for  any 
size.     Short  division  plates  are  also  supplied  for  mak- 
ing sectional  blocks  for  "fillers."    Two  sets  of  stand 
ard  division  plates  are  furnished  with  each  mold,  s» 
that  it  can  be  filled  twice  daily,  making  twenty  block? 


148  Concrete  Silos 

A  special  bender  for  making  the  rods  and  links  is 
included  in  the  outfit  if  desired,  or  these  will  be  fur- 
nished by  the  company  to  those  who  do  not  care  to 
prepare  their  own.  A  bender  can  also  be  secured  for 
changing  dividing  plates  from  one  radius  to  another. 

Iron  or  steel  door  frames  are  either  secured  from 
the  company,  or  a  pattern  only  is  bought,  allowing  the 
contractor  to  have  his  frames  made  at  the  nearest 
foundry.  All  frames  are  curved  to  a  radius  of  8  feet, 
in  order  to  avoid  multiplication  of  parts,  as  the  dif- 

4  SIDES  KEMOWBLE  SOON  AFTEff  F/LUNG. 
B.  G4V/TY  COXES  S  REJNFWCEMENT 

SUPPORT. 
C 

WPOS/7XW. 


0.  SLOT  COVER. 
£  CURVED  STEEL 
F  ADJUSTABLE  CLAMPS. 


Hurst  Silo  Block  Mold 


ference  of  curvature  is  scarcely  noticeable  in  the  width 
of  a  door  when  this  frame  is  used  on  other  sizes.  The 
frame  provides  a  beveled  rabbet  for  a  wood  door,  and 
carries  loops  to  connect  with  the  reinforcing  rods  of 
the  adjoining  blocks. 

Steps  are  bolted  to  the  doors,  or  ladder  steps  of 
steel  with  ends  flattened  are  embedded  in  the  mortar 
between  the  courses  of  blocks. 

If  a  chute  is  desired,  %x5-inch  bolts  are  inserted 
in  every  third  mortar  joint  on  either  side  of  the  door 
frames,  beginning  8  feet  from  the  ground.  Similar 


Concrete  Silos 


149 


bolts  also  extend  upward  every  4  feet  in  the  joints  of 
the  top  course  of  blocks,  to  anchor  the  roof,  which 
may  be  of  any  type. 

Dave-tail  Silo  Block.  The  Lansing  Company,  Lan- 
sing, Mich.,  manufacture  what  is  called  the  Dove-tail 
silo  block  ma- 
chine. This  ma- 
chine makes  a 
hollow  silo  block 
with  dove-tail 
openings  at  each 
end.  Where  these 
openings  come 
together,  they  fit  Dove-tali  siio  Block, 

over  a  small  countersunk  hole  in  the  middle  of  the 
block  below.  The  dove-tail  opening  is  filled  with  soft 
mortar  which  finds  its  way  into  the  countersunk  hole 
and  binds  the  blocks  together  both  horizontally  and 
vertically.  A  small  groove  is  also  provided  in  the  top 
of  each  block  for  the  purpose  of  laying  in  reinforcing 
wire. 

The  machine  consists  of  a  base  and  a  flask  or  mould. 
The  mould  consists  of  a  front  and  back  plate,  two 
end  plates,  center  cores,  dove-tail  end  cores,  extra 
face  plate  for  half  size  blocks,  and  dividing  plate.  The 
two  end  plates  fit  into  lugs  in  the  front  plate  and  the 
back  plate  is  held  in  position  by  two  end  levers.  The 
mould  is  of  the  self-truing  type  and  will  produce 
blocks  of  an  attractive  design.  It  is  furnished  in  12, 
14,  16  and  18-foot  diameters.  Each  size  of  block  can 
also  be  used  for  a  silo  of  a  diameter  2  feet  larger 
than  the  stated  size.  It  is  equipped  for  either  9  or 
10-inch  blocks,  16  inches  long,  8  inches  high.  The 


150 


Concrete  Silos 


regular  equipment  consists  of  rock  face  design,  but 
the  manufacturers  also  furnish  a  plain  design. 

Ideal  System.    The  Ideal  Concrete  Machinery  Com- 
pany, Cincinnati,  Ohio,  supplies  molds  for  silo  blocks 


Method  of  Constructing  Ideal  Silos 


Concrete  Silos 


151 


in  the  standard  8x8x16  inch  size  in  practically  all  the 
faces  designed  by  this  company  for  straight  building 
blocks.  These  silo  attachments  can  be  set  on  the 
standard  Ideal  block  machine  base  outfit,  and  the  silo 
blocks  are  cast  with  two  4x6  inch  core  openings  the 
same  as  the  building  blocks.  Attachments  are  pro- 
vided for  making  blocks  on  a  5,  7  or  9-foot  radius. 

As  each  block  is  cast,  a  piece  of  half  round  iron 
makes  a  groove  in  the  top,  about  1  inch  from  the  out- 
side face,  this  groove  accommodating  the  reinforcing 
ring  when  the  blocks  are  laid  up.  These  rings  are 
fastened  at  the  ends  to  the 
door  frames  as  shown  in  the 
illustration ;  or  if  the  builder 
has  at  hand  the  proper  dies 
for  cutting  threads,  he  can 
thread  the  ends  of  each  ring 
and  draw  the  ring  to  the 
proper  tension  with  a  nut. 

The  door  frames  consist  of 
U-bars  for  uprights  con- 
nected at  3-foot  intervals  by 
4-iiich  I-beams.  The  uprights 
are  set  just  the  thickness  of 
the  door  from  the  inner  face 
of  the  block,  so  that  when 
the  door  is  in  place  the  inte- 
rior will  present  a  smooth 
surface. 

It  is  recommended  that  the  climax  Blocks 

inside  of  the  silo  be  plastered  with  cement  mortar,  ap- 
plied, preferably  with  a  trowel,  and  then  going  over  the 
entire  surface  with  a  stiff  brush  and  cement  grout. 


152 


Concrete  Silos 


Climax  Silo  Blocks.  The  equipment  for  making 
these  blocks  is  furnished  by  the  Climax  Manufactur- 
ing Company,  Anderson,  Indiana.  The  blocks  are  20 
inches  long,  10  inches  high,  and  4  inches  thick.  Each 
block  carries  lugs  on  the  underside  and  recessed  groove 
on  the  upper  side,  holding  the  blocks  in  perfect  posi- 
tion when  they  are  placed  together.  The  blocks  them- 
selves are  reinforced  with  any  wire  available,  and  a 
No.  9  wire  is  also  used  in  the  grooves  as  the  blocks  are 
laid  up. 

Kenny  System.  The 
Kenny  concrete  blocks 
are  made  with  a  groove 
in  the  top  for  receiv- 
ing the  reinforcing 
rod,  which  is  contin- 
ued in  one  piece 
around  the  entire  silo, 
locking  it  over  a  key 
block,  as  shown  in  the 
accompanying  cut. 

The  vertical  grooves 

in     the      ends     Of     the        Wires  Locked  Over  Key  Block 

blocks  form  an  opening  2  inches  in  diameter  between 
the  blocks  when  laid  in  the  wall;  this  opening  is  filled 
with  cement  mortar. 

The  blocks  are  made  on  a  double  machine,  turning 
out  two  blocks  at  one  operation,  and  are  24  inches  long, 
8  inches  high,  and  4  inches  thick. 

Anchor  Silo  Blocks.  This  block  makes  a  double 
wall,  with  a  continuous  air  space.  It  is  controlled  by 
the  Anchor  Concrete  Stone  Company,  Rock  Rapids, 
Iowa.  Each  block  is  made  in  two  separate  sections, 


Concrete  Silos 


153 


bound  together  with  four  ^-inch  galvanized  iron 
rods,  8  inches  long  and  turned  1  inch  at  each 
end.  The  Standard 
Anchor  machine 
makes  a  block  8x8x 
24  inches,  while  the 
Junior  Anchor  ma- 
chine makes  a  block 
8x8x16  inches.  Each 
machine  makes 
blocks  to  fit  any  de- 
sired radius  of  silo. 
This  is  accomplished 
by  having  the  mold 
box  equipped  with 
inside  steel  plates 
which  can  be  ad- 
justed by  set  screws 
to  the  desired  curve. 
The  interior  section 
of  the  block  is  cast 
with  a  groove  in  the 
top  in  which  rein- 
forcing  can  be 

placed.  Anchor  Blocks  Laid  Up  in  Wail 

Keystone  Cement  Slab  Silo.  This  system  is  con- 
trolled by  the  Minnesota  Keystone  Silo  Company,  Min- 
neapolis, Minn.  The  blocks  or  slabs  used  in  a  Key- 
stone silo  have  a  special  design,  the  ends  being  wider 
by  3  inches  than  the  center  of  the  slab.  This,  in  addi- 
tion to  the  tongue-and-groove  edges,  makes  of  each 
block  a  key  which  securely  locks  the  adjoining  slabs. 
The  slabs  or  blocks  are  24  inches  long,  3  inches  thick, 


154 


Concrete  Silos 


16  inches  wide  at  the  center  and  13  inches  at  the  mid- 
dle. Each  block  is  reinforced  with  two  %-inch  steel 
rods,  each  end  of  each  rod  projecting  into  a  small 
cavity.  When  the  blocks  are  laid  up  these  ends  are 
connected  and  brought  to  tension  by  a  special  tool. 
The  cavity  is  then  filled  with  concrete. 

Millers'  Sectional  Interlocking  Block  Silo.  This 
system  is  controlled  by  the  Goshen  Concrete  Tile 
Manufacturing  Company,  Goshen,  Indiana.  The  blocks 
in  this  system  are  solid 
blocks  made  of  slush 
concrete  interlocking 
at  all  edges.  A  double 
rod  of  5-16-inch  iron 
through  each-  bloc.k 
makes  the  reinforcing 
and  forms  an  eye  at 
the  end  of  each  block. 
The  blocks  are  fas- 
tened together  by 
means  of  a  staple 
passing  through  these 
eyes,  the  open  spaces  around  the  eyes  and  staples 
then  being  filled  with  mortar.  The  door  frame  used 
in  connection  with  these  blocks  is  constructed  of  chan- 
nel iron.  On  the  side  of  the  door  jamb  toward  the  block, 
there  are  eyes  every  12  inches  to  correspond  with  the 
eyes  on  the  block,  so  the  door  frame  and  blocks  are 
locked  together  by  means  of  staples  and  spaces 
filled  with  mortar,  making  joints  same  as  between  the 
blocks  themselves. 

Perfect  Cement  Blocks.  This  is  made  on  the  per- 
fect cement  block  machine,  manufactured  by  J.  J. 
Coyne,  Fond  du  Lac,  "Wisconsin.  This  machine  makes 


Miller's 

Interlocking 

Block 


Concrete  Silos  155 

a  hollow  block  of  two  types,  the  two  parts  in  the 
block  being  connected  either  by  a  web  of  concrete 
or  by  steel  spacers.  The  blocks  are  made  8  inches 
high,  9  inches  thick  and  24  inches  long,  with  21/2-inch 
air  space.  The  blocks  interlock  in  both  directions  and 
have  a  groove  on  top  for  reinforcement. 


Perfect  Reinforced  Block.  This  system  is  the  prod- 
uct of  the  Perfect  Reinforced  Cement  Silo  and  Cis- 
tern Company,  Delaware,  Ohio.  The  Perfect  Silo  is 
built  with  blocks  2  feet  long,  1  foot  high  and  4  inches 
thick. 

Each  block  is  reinforced  with  two  iron  rods  run- 
ning lengthwise  of  the  block,  6  inches  apart.  Each 
rod  is  looped  or  turned  6  inches  from  the  end.  These 
loops  in  the  rods  coincide  with  the  holes  that  are 
formed  edgewise  through  the  block,  1  inch  in  diame- 
ter and  6  inches  from  either  end.  In  laying  the  blocks 
these  1-inch  openings  are  filled  with  cement  grout  and 
the  rod  or  dowel  pin  is  pressed  through  the  soft 
cement,  connecting  the  two  blocks.  Each  pin  is  in- 
serted in  such  a  way  that  it  passes  entirely  through 
one  block  and  half  way  through  the  block  above  and 
the  one  below.  By  this  arrangement  of  loops  and 
dowel  pins,  inserted  in  the  holes  through  the  blocks, 
and  the  use  of  half  blocks,  joints  are  broken  in  the 
same  way  as  when  an  ordinary  brick  wall  is  laid.  This 
provides  for  a  continuous  lateral  reinforcement  around 
the  silo  every  6  inches,  and  the  dowel  pins  that  run 
through  the  blocks  from  the  bottom  to  the  top  of  the 


156  Concrete  Silos 

silo  form  a  vertical  reinforcement  every  foot.  A  strip 
of  netting  composed  of  7  longitudinal  and  12  vertical 
steel  wires,  imbedded  in  the  block  just  beneath  the 
outer  surface,  is  designed  to  prevent  any  liability  of 
cracking  of  the  face  of  the  block.  To  unite  the  blocks 
and  to  overcome  the  outward  pressure  or  thrust,  a 
2-ply  twisted  steel  cable  of  No.  8  wire  is  laid  outside 
the  dowel  pins  between  each  course  of  blocks,  in 
grooves  provided  in  the  edge  of  the  blocks  for  that 
purpose,  and  imbedded  in  the  mortar  in  which  they 
are  laid.  The  ends  of  these  cables  are  looped  about 
a  continuous  gas  pipe,  which  extends  from  the  top  to 
the  bottom  of  the  structure,  through  the  blocks  each 
side  of  the  doorway,  in  place  of  dowel  pins.  This  same 
gas  pipe  also  passes  through  holes  in  the  ends  of  the 
ladder  rounds. 

Zagelmeyer  System.  This  method  of  making  silo 
blocks  is  the  invention  of  the  Zagelmeyer  Cast  Stone 
Block  Company  of  Bay  City,  Mich.,  and  is  identical 
with  the  system  used  by  this  company  for  making 
building  blocks,  except  that  the  silo  blocks  are  made 
to  fit  the  curve  of  the  silo  instead  of  being  straight. 
The  molds,  which  are  of  sheet  steel,  are  assembled  in 
multiple  form  on  roller  bearing  trucks,  each  truck  car- 
rying molds  for  thirty  silo  blocks.  The  truck  is  then 
carried  under  the  discharge  end  of  the  mixer  and  filled 
with  slush  concrete. 

Each  block  carries  two  air  spaces,  and  has  a  depres- 
sion in  the  top  for  carrying  a  continuous  circle  of  rein- 
forcing around  the  silo. 

Molds  are  made  in  both  rock  face  and  plain.  The 
blocks  can  if  desired  be  given  a  granite  or  other  orna- 
mental face,  similar  to  the  Zagelmeyer  building  blocks. 


CHAPTER   XVII 

DOORWAYS,  DOORS,  ROOFS,  ETC. 

These  topics  have  been  dealt  with  in  connection 
with  some  of  the  systems  treated,  so  that  in  this  chapter 
it  is  scarcely  necessary  to  do  more  than  take  up  some 
general  features  of  these  parts  of  the  silo. 

Doorways.  Doorways  are  of  two  types,  known  as 
intermittent  and  continuous.  These  doorways  are  both 
good,  and  it  is  a  matter  of  individual  preference  as  to 
the  one  to  select,  although  the  separate  openings  are 
preferred  by  a  great  many  silo  users.  These  openings 
are  usually  2  feet  wide  and  3  feet  high,  and  are  spaced 
about  3  or  4  feet  apart.  This  type  of  doorway  makes  a 
stronger  wall,  but  more  difficulty  is  experienced  in 
removing  the  silage  for  feeding  than  with  the  con- 
tinuous door. 

An  easily  constructed  intermittent  door  form  for  a 
solid  concrete  wall  silo  is  suggested  by  the  Association 
of  Portland  Cement  Manufacturers  as  shown  in  the 
illustration.  Make  a  frame  of  2x6  inch  lumber  as 
shown.  Then  prepare  a  second  frame  of  2x2  pieces,  and 
nail  it  around  the  first.  This  will  provide  an  offset  or 
jamb  of  2  inches  in  the  concrete,  to  receive  the  door 
from  the  inside.  This  form  should  be  made  so  that  it 
will  fit  closely  between  the  inside  and  outside  wall 
forms. 

The  method  of  constructing  a  form  for  a  continuous 
door  opening  is  similar  to  the  one  for  separate  open- 
ings. Two  pieces  of  lumber  2x6  inches  are  cut  5  feet 
long.  Two  holes  are  then  bored  through  each  piece. 

(157) 


158 


Concrete  Silos 


These  holes  are  2  feet  apart  and  2  inches  from  the  edge. 
The  pieces  are  then  ripped  through  the  holes.  A  piece 
of  2x2  inch  lumber,  beveled,  is  then  nailed  to  the  4-inch 
piece  thus  made.  Cleats  are  nailed  across  the  two  pieces 
which  were  cut.  These  cleats  are  to  hold  cross-strips 
between  the  two  uprights,  for  the  purpose  of  keeping 
the  door  forms  the  right  distance  apart. 


2x2' 


2x6' 


Form    for   Intermittent    Doorway. 

When  setting  the  form  into  the  molds,  the  ladder  or 
door  rods  are  placed  in  the  holes  of  the  door  form.  This 
method  of  door-jamb  construction  has  been  in  use  for 
eight  or  ten  years,  and  has  been  found  satisfactory. 
The  method  of  reinforcing  across  both  types  of  door 
openings  is  also  shown  herewith. 

Doors.  The  doors  for  the  continuous  doorway  may 
be  made  of  2-inch  planking,  preferably  tongue-and- 
grooved.  The  doors  should  be  34  inches  in  width  and 
30  inches  in  height.  Five  pieces  of  planking  6  inches 
wide,  or  4  pieces  8  inches  wide  may  be  used  con- 
veniently. A  %-inch  hole  is  drilled  on  the  vertical 


Concrete  Silos 


159 


center  line  of  each  plank  to  accommodate  the  bolt  and 
hook  by  which  the  door  is  held  to  the  horizontal  rein- 
forcing across  the  door  opening.  The  bolts  used  have  a 
screw  eye  on  the  outer  side  to  which  hangs  a  hook  made 
of  heavy  steel  wire. 

Non-continuous  doors  are  perhaps  easier  to  build 
than  continuous  doorways,  and  if  the  owners  are  satis- 
fied that  they  provide  sufficient  room  for  getting  the 


Method  of  Fastening  Reinforcing  When   Silo  Is  Built  With 
Continuous    Door    Opening. 

silage  out  conveniently,  there  is  no  objection  to  their 
use,  although  on  the  other  hand,  they  possess  no  great 
advantage  over  doors  of  the  continuous  type.  The 
arguments  often  heard  that  the  non-continuous  door 
silo  is  a  stronger  type  than  the  other,  and  vice  versa, 


160 


Concrete  Silos 


carry  little  weight,  as  either  type  may  'be  made  suffi- 
ciently strong. 

Non-continuous  doors  are  often  put  in  with  a  dis- 
tance of  about  2%  feet  between  them,  but  the  spacing 
may  vary  to  suit  the  individual  owner.  In  all  cases 
the  arches  between  the  doors  must  contain  an  amount 


Method   of   Reinforcing   Around   Intermittent   Door   Openings. 


of  reinforcing  equivalent  to  the  full  amount  of  hori- 
zontal reinforcing  put  around  the  silo.  Thus,  if  the 
doors  are  3  feet  in  height,  with  a  distance  of  2%  feet 
between  them,  the  horizontal  reinforcing  in  the  space 


Concrete  Silos  161 

between  the  doors  should  be  equivalent  in  amount  to 
that  placed  in  5l/2  feet  of  the  wall  where  there  are  no 
doors. 

The  doors  may  best  be  made  of  two  thicknesses  of 
Ix6-inch  matched  flooring  with  a  layer  of  tar  paper 
between.  The  Ix6-inch  boards  are  held  together  by 
two  Ix4-inch  cleats  across  the  top  and  bottom,  and  one 
2x4-inch  cleat  across  the  center.  The  middle  cleat  is 
made  larger  than  the  others  in  order  to  take  care  of  the 
strain  caused  by  the  large  bolt  in  the  center.  A  2x4, 
40  inches  long,  or  a  similar  piece  of  material,  is  placed 
on  the  bolt,  making  a  large  "button"  by  which  the  door 
is  held  to  the  wall. 

The  Roof.  Perhaps  the  greatest  advantage  of  a 
roof  is  the  lessened  liability  of  the  silage  freezing.  Not 
only  is  it  impossible  to  prevent  freezing  in  severe 
weather  unless  the  silo  is  provided  with  a  roof,  but 
during  snowy  or  rainy  weather  the  silage  is  mixed 
with  snow  or  wet  down  with  rain.  Furthermore,  a  silo 
without  a  roof  becomes  a  catching  place  for  husks,  dust 
or  anything  carried  in  the  wind  and  a  favorite  feeding 
ground  for  the  neighborhood  pigeons  and  birds. 
Although  many  silos  are  not  provided  with  roofs  and 
the  live  stock  eagerly  eat  the  silage  from  them,  it  is 
evident  that  a  roof  would  not  only  reduce  the  amount 
of  frozen  silage,  actually  save  silage  and  preserve  its 
quality,  but  be  worth  its  cost  in  making  a  more  pleasant 
place  to  feed  from  in  bad  weather.  The  roof  is  also 
valuable  in  protecting  and  strengthening  the  silo  and  in 
adding  to  its  appearance. 

A  door  for  filling,  large  enough  to  admit  the  carrier 
or  elevator  from  the  ensilage  cutter,  should  be  placed  in 
the  roof.  A  simple  trap  door  may  be  used  for  this  pur- 


162  Concrete  Silos 

pose,  but  a  dormer  window  with  glass  is  preferable. 
Some  light  should  be  admitted  to  the  silo  for  if  not  it 
will  be  necessary  to  use  a  lantern  when  removing  the 
silage. 

The  pitch  of  the  silo  roof  may  vary  from  one- 
quarter  to  one-half.  The  steeper  roof  permits  the  silo 
to  be  filled  above  the  top  of  the  wall  so  as  to  be  nearly 
full  after  settling.  A  flat  roof  does  not  permit  the 
silage  to  be  elevated  to  a  point  high  enough  to  do  this, 
does  not  give  the  workman  room  for  work  during 
filling,  and  does  not  shed  the  snow  like  a  steeper  roof. 

.While  roofs  of  various  types  are  used  with  concrete 
silos,  it  is  most  desirable  that  the  roof  be  of  concrete, 
thus  making  this  part  of  the  silo  as  durable  as  »ny 
other. 

In  some  systems,  special  roof  forms  are  provided ; 
but  where  there  are  not  obtainable  a  concrete  roof  can 
be  laid  4  inches  thick  over  a  temporary  wooden  form, 
which  will  be  left  in  place  two  or  three  weeks.  The 
concrete  should  lbe  reinforced  with  steel  rods  %-inch  in 
diameter.  Some  of  the  rods  are  laid  like  the  spokes  of 
a  wheel,  1-inch  from  the  under  side  of  the  roof.  At  the 
eaves  the  rods  are  18  inches  apart ;  but  every  other  rod 
runs  only  half-way  to  the  peak,  where  it  is  tied  to  a 
horizontal  ring  extending  entirely  around  the  roof. 
There  are  four  of  these  horizontal  rings  equally  spaced 
from  the  eaves  to  the  center  of  the  roof.  Where  the 
straight  or  radial  rods  meet  at  the  peak  they  should  be 
hooked  and  securely  tied  together.  In  the  eaves  an 
additional  ring  is  placed,  around  which  are  hooked  the 
outer  ends  of  the  straight  rods. 

Eaves  on  a  concrete  roof  are  not  absolutely  neces- 
sary, but  add  much  to  the  appearance  of  the  silo. 


Concrete  Silos 


163 


Iron  Roof.  An  iron  roof  for  silos  is  made  by  the 
C.  ('.  Fonts  Company,  Middletown,  Ohio.  This  roof  is 
made  in  sections  readily  bolted  together.  It  is  of  pure 
iron,  20  to  24  gauge,  and  is 
equipped  with  a  large  trap 
door  for  filling.  This  door  fits 
over  a  raised  rim  in  the  roof, 
making  it  weatherproof.  These 
roofs  are  made  with  a  ventila- 
tor and  a  heavy  wired  glass  at 
the  top,  admitting  sufficient 
light  to  light  up  the  interior 
of  the  silo.  One  advantage 
of  this  kind  of  a  roof  is  that 
sections  of  it  can  be  left  off 
while  the  silo  is  being  filled. 
This  will  allow  of  the  silo 
being  filled  to  its  full  capac- 
ity, while  the  settling  of  the 
silage  will  be  sufficient  to  give 
working  room  when  it  is  de- 
sired to  begin  feeding  from 
the  silo. 

Winner  Extension  Silo 
Roof.  The  special  feature  of  M 
this  roof,  which  is  made  by 3 
the  Silo  Specialty  Manu-  £ 
facturing  Company  at  Clinton,  \\  n  >i  •;.. 
Iowa,  is  that  it  allows  the  user  to  utilize  the  entire 
space  of  the  silo.  That  is,  the  roof  opens  outward  from 
the  peak,  so  that  the  silo  can  be  filled  above  the  height 
of  the  walls.  As  the  silage  settles  the  roof  is  closed, 
giving  the  contents  of  the  silo  complete  protection 
against  the  elements. 


164  Concrete  Silos 

The  method  of  operation  of  this  roof  is  well  shown 
in  the  illustration.  It  has  a  metal  roof  consisting  of 
separate  segments  which  are  hinged  at  the  bottom  and 
can  be  opened  until  they  stand  vertical.  When  they  are 
opened  for  filling  the  silo  the  spaces  between  the  seg- 
ments are  protected  by  wire  mesh. 

Buckeye  Silo  Roof.  This  is  a  sheet  metal  roof,  made 
in  gambrel  design  with  dormer  window.  It  is  made  by 
the  Thomas  &  Armstrong  Company,  London,  Ohio.  The 
same  company  also  makes  all-steel  silo  doors,  and  other 
silo  equipment. 

Air-Tight  All,  Steel  Door  Frame.  This  is  a  continu- 
ous door  manufactured  by  the  Silo  Specialty  Manufac- 
turing Company  at  Clinton,  Iowa.  This  is  an  inflexible, 
unbreakable,  steel  door  frame,  requiring  no  packing  to 
make  a  tight  door. 


CHAPTER  XVIII 
How  TO  INCREASE  THE  SILO  BUSINESS. 

A  firm  of  contractors  and  supply  dealers  in  Sioux 
City,  Iowa,  have  adopted  a  novel  method  of  promot- 
ing the  silo  end  of  the  business  by  erecting  a  sample 
silo  on  their  grounds  'and  utilizing  the  lower  part  of 
it  for  office  purposes.  This  company  is  fortunately 
situated  at  the  stock  yards,  within  75  feet  of  the  Live 
Stock  National  Bank,  so  that  the  silo  is  just  where  it 
will  catch  the  attention  of  the  men  it  is  desired  to 
reach.  It  carries  a  conspicuous  sign,  calling  attention 
to  the  fact  that  the  structure  is  for  inspection  and 
that  the  office  is  inside.  Leaflets  are  also  sent  out 
among  the  farmers  in  the  territory  telling  them  of  this 
exhibition  silo  and  showing  illustrations  of  it  and 
also  of  silos  which  the  company  has  constructed  on 
farms  in  the  vicinity. 

The  sample  silo  has  at  least  two  advantages  as  an 
advertising  asset.  There  is  no  doubt  but  many  farm- 
ers will  be  attracted  by  it  and  will  step  in  "just  to 
look  around"  out  of  curiosity.  If  the  sales  work  is 
what  it  should  be,  a  fair  proportion  of  these  will  ulti- 
mately buy.  The  prospective  customer  is  thus  brought 
right  to  the  office  instead  of  making  it  necessary  to 
go  out  after  him,  and  any  salesman  knows  what  this 
means,  both  in  the  saving  of  time  and  the  advantage 
of  having  the  man  on  your  own  ground  and  with  a 
confessed  interest  in  what  you  have  to  sell. 

There  will  be  still  other  men  who  know  that  they 
want  a  silo  and  would  come  to  the  office  whether  there 

(165) 


166 


Concrete  Silos 


were  -a  sample  on  exhibition 
or  not.  The  advantage  of- 
fered by  the  sample  silo  in 
dealing  with  these  men  is 
that  the  deal  can  be  closed 
up  much  more  promptly, 
avoiding  the  necessity  of 
spending  time  and  expense 
money  to  take  the  prospect 
'out  to  see  some  of  the  silos 
on  surrounding  farms. 

By  getting  a  man  right  in 
the  office  the  system  of  con- 
struction can  also  be  demon- 
strated, arousing  the  interest 
of  the  farmer  in  the  simplic- 
ity of  the  equipment,  the  de- 
vice by  which  the  walls  are 
kept  true  to  line,  etc.  A 
small  section  of  the  well  can 
also  be  cut  away,  if  desired, 
exposing  the  reinforcement 
and  revealing  the  stability 
of  construction  and  the  hard 
and  enduring  nature  of  the 
material. 


Silo  Inspection  Trip  Conducted  by  a  Cement  Company. 


Concrete  Silos  167 

While  a  sample  silo  of  this  kind  costs  a  little  money, 
where  a  favorable  location  can  be  secured  it  would 
seem  to  be  a  very  valuable  advertising  asset ;  and  espe- 
cially would  this  be  true  in  thinly  populated  districts, 
where  a  contractor,  located  in  a  central  market  town, 
can  bring  to  his  office  men  whom  he  would  otherwise 
have  to  go  many  miles  to  reach. 

Sample  silos  of  a  permanent  nature  are  located  on 
the  grounds  of  many  of  the  state  fairs,  while  tempo- 
rary sample  sections  are  frequently  put  on  display  at 
various  expositions.  These  are  usually  put  up  by  the 
promoters  of  the  various  systems  of  construction,  and 
they  serve  the  double  purpose  of  stimulating  a  demand 
for  silos  and  of  reaching  contractors  and  interesting 
them  in  this  class  of  construction. 

Some  of  the  more  progressive  manufacturers  have 
well  devised  campaigns  which  are  put  into  effect  for 
the  benefit  of  contractors  who  buy  their  outfits.  In 
addition  to  furnishing  him  with  suitable  printed  mat- 
ter, albums  of  photographs,  etc.,  each  contractor  is 
requested  to  send  in  to  the  company  the  names  of  farm- 
ers in  his  locality  who  should  own  silos — not  a  miscel- 
laneous list  of  names,  but  a  list  which  is  carefully  se- 
lected and  not  too  large  to  have  devoted  to  it  some 
personal  work  on  the  part  of  the  contractor  himself. 
To  these  people  the  manufacturer  sends  out  a  letter 
setting  forth  the  advantages  of  concrete  silos  in  a  brief 
way  and  calling  attention  to  the  fact  that  the  local 
contractor  is  now  prepared  to  build  such  a  silo  for 
them.  These  letters  are  followed  up  at  suitable  inter- 
vals by  letters  sent  out  by  the  contractor,  but  the  copy 
for  which  is  supplied  by  the  manufacturer ;  and  in  the 
mean  time  it  is  expected  that  the  contractor  is  doing 
more  or  less  personal  work  with  these  people,  at  least 


168 


Concrete  Silos 


to  the  extent  of  taking  advantage  of  casual  meetings 
when  they  are  in  town  if  he  does  not  get  out  to  see 
them  at  their  own  homes. 
Photographs  are  won- 
derfully helpful.  In  addi- 
tion to  the  albums  sent  out 
with  an  outfit,  some  man- 
ufacturers stimulate  busi- 
ness for  their  customers  by 
sending  out  additional 
photographs  from  time  to 
time.  These  may  be  of 
new  silos  just  completed, 
especially  if  there  is  any 
unusual  feature  about  the 
silo  or  if  it  is  for  some 
person  of  prominence;  or 
they  may  show  how  a  con- 


Sample  Silo  and  Office  at  Sioux  City,  Iowa. 


Concrete  Silos 


169 


crete  silo  has  successfully  withstood  a  recent  fire,  tor- 
nado or  earthquake. 

The  contractor  can  also  assist  in  this  part  of  the 
work  by  having  photographs  made  of  the  silos  which 
he  erects  and  using 
them  in  his  own  local  * 
work  as  well  as  sup- 
plying them  to  the 
manufacturer  for  the 
betterment  of  the  in- 
dustry as  a  whole. 

Some  silo  builders 
have  secured  permis-   ' 
sion  from  their  cus- 
tomers to  place  at  the 
entrance  to  the  farm 
a  neat  sign  bearing 
an  inscription  some-   >< 
thing  like  this: 


The  Concrete  Silo 
On    This    Farm    Was 

Built  by  the 

Company.      Drive     in 
and  Examine  It. 


In  most  localities 
the  principal  opposi- 
tion to  be  combated 
is  from  the  wood  silo. 
For  the  representa- 
tive of  this  type  is  Silo  on  Illinois  State  Pair  Grounds. 

more  frequent  and  more  persistent  than  any  other,  and 
he  is  in  fact  the  only  silo  salesman  whom  many  a 


170  Concrete  Silos 

farmer  sees.  This  is  because  the  wood  silo  is  a  factory 
product,  capable  of  being  shipped  out  " ready  made" 
under  the  supposition  that  the  farmer  can  put  it  up 
himself,  thus  lending  itself  readily  to  the  building  up 
of  a  large  sales  organization.  These  agents  who  are 
sent  out  over  the  country  know  that  their  main  business 
is  to  get  orders,  and  an  important  part  of  their  equip- 
ment for  so  doing  is  a  handful  of  misinformation  about 
concrete  as  a  silo  building  material. 

But  with  no  knowledge  to  the  contrary,  a  farmer 
is  perhaps  not  to  be  blamed  if  he  believes  the  man 
who  assures  him  positively  that  the  acids  in  silage  will 
eat  out  a  concrete  silo  in  two  or  three  years.  It  is 
necessary  that  this  propaganda  be  combated,  and  the 
authoritative  statements  which  have  been  given  out  by 
so  many  of  the  agricultural  schools  of  the  country 
should  be  given  wide  publicity,  as  they  will  go  a  long 
way  toward  forming  in  the  mind  of  the  user  of  silos  a 
saner  and  more  correct  view  of  the  situation.  State- 
ments of  this  nature  can  well  be  included  in  some  of  the 
printed  matter  sent  out  by  contractors  to  develop  the 
silo  business ;  and  editors  of  newspapers  should  be  pre- 
vailed upon  to  print  matter  pertaining  to  silos  from 
time  to  time. 

It  is  generally  conceded  that  advertising  in  local 
newspapers  on  the  part  of  contractors  will  form  a  valu- 
able adjunct  to  other  forms  of  development  work.  If 
this  advertising  can  be  given  a  local  turn  at  times,  such 
as  printing  illustrations  of  silos  which  have  been  built 
in  the  neighborhood,  or  letters  of  recommendation  from 
local  men  who  are  pleased  with  their  silos,  this  adver- 
tising will  have  a  double  value. 

A  farmer  can  often  be  interested  in  concrete  silos 
by  having  pointed  out  to  him  the  fact  that  most  of 


Concrete  Silos 


171 


the  materials  can  very  likely  be  found  right  on  his 
own  farm  and  that  he  will  be  the  gainer  to  that  ex- 
tent. One  Iowa  contractor  has  taken  a  somewhat  novel 
way  to  emphasize  this  point.  He  says  in  his  adver- 
tising: 

//  you  have  sand  and  gravel  on  your  own 
farm   or   nearby,   we   will    buy   it   from   you. 
This  representation  to  the  farmer  that  he  is  going 
to  get  some  of  his  money  back  immediately  will  prob- 


Exhibition  Silo  at  Texas  State  Fair. 


172  Concrete  Silos 

ably  be  more  convincing  than  would  a  mere  statement 
of  the  saving  effected  by  the  use  of  materials  from  his 
farm. 

A  considerable  amount  of  promotion  work  on  all 
kinds  of  silos  can  be  carried  on  during  the  winter, 
when  the  farmer  is  not  so  busy  and  is  looking  ahead 
to  the  improvement  of  his  farm. 

The  farmer  as  a  class  usually  looks  farther  ahead 
than  any  other  man.  Of  course,  there  are  farmers 
who  live  from  hand  to  mouth,  as  the  saying  is,  just  the 
same  as  can  be  found  in  any  other  calling ;  but  for  the 
most  part  you  will  find  among  well-to-do  farmers  more 
accurately  detailed  plans  for  the  future  than  among 
almost  any  other  men  that  one  might  name.  The  very 
nature  of  their  occupation  leads  them  to  plan  that  way. 
Practically  nothing  that  a  farmer  does  comes  to  frui- 
tion until  a  considerable  time  after  it  is  started.  In 
this  sense  he  is  'always  working  for  the  future.  His 
grain  is  planted  in  the  spring  and  harvested  in  the 
fall;  the  kind  of  stock  that  he  will  raise  is  made  the 
subject  of  serious  study  sometimes  years  ahead;  the 
products  of  his  farm  must  be  stored  away  at  certain 
seasons  for  future  use ;  and  his  bank  account,  which  is 
swelled  at  periods  of  the  year  when  products  are  being 
sold,  must  be  conserved  to  provide  for  the  times  when 
there  will  be  no  income. 

It  is  perhaps  for  some  of  these  reasons  that  con- 
crete products  manufacturers  have  found  the  farmer 
market  a  most  satisfactory  and  profitable  one.  It 
might  be  mentioned  also  that  the  farmer  is  a  good  ad- 
vertiser. He  delights  to  make  every  business  transac- 
tion the  subject  of  conversation.  Where  the  city  busi- 
ness man  will  buy  a  thing  in  a  hurry  and  promptly 


. 


Concrete  Silos  173 

forget  about  it,  the  farmer  will  buy  slowly  and  only 
after  much  discussion,  and  once  having  bought  he 
will  talk  about  his  purchase  for  some  time  afterward. 
Sell  him  what  he  believes  to  be  a  good  product  'and  the 
chances  are  that  you  will  soon  get  other  orders  from 
the  same  neighborhood;  but  if  he  believes  that  you 
have  not  treated  him  right,  it  will  be  very  difficult  to 
sell  to  any  of  his  neighbors  for  some  time  to  come. 

In  some  localities  the  manufacturers  of  concrete 
silo  blocks  and  staves  have  discovered  that  they  can 
keep  business  going  at  a  fairly  brisk  pace  throughout 
the  winter  by  showing  the  farmers  the  advantage  of 
hauling  these  things  in  the  winter  time.  In  fact,  it 
seems  to  have  been  the  farmers  themselves  who  first 
discovered  the  advantages  of  such  a  system;  but  the 
products  men  have  not  been  slow  to  take  advantage 
of  it  in  a  number  of  instances. 

In  one  Wisconsin  town  a  block  manufacturer  was 
asked  a  quotation  on  a  certain  bill  of  silo  blocks,  in  the 
middle  of  winter. 

"They  will  cost  you  16  cents  apiece/*  said  the 
manufacturer. 

"All  right,  I  am  satisfied/'  said  the  farmer;  "I'll 
take  the  first  load  of  them  out  with  me  today/' 

The  block  man  was  alive  to  the  advantage  of  quick 
sales,  but  he,  at  the  same  time,  did  not  want  to  rush 
his  product  out  without  sufficient  time  to  cure,  so  he 
said: 

"Those  -blocks  are  only  eight  days  old.  You  had 
better  leave  them  here  for  a  couple  of  weeks  longer 
and  let  them  cure.  If  you  take  them  now  it  is  pretty 
sure  there  will  be  a  number  of  them  broken  when  you 
get  them  home." 


174  Concrete  Silos 

" There  is  no  time  like  the  present,"  was  the  reply 
of  the  farmer,  or  words  to  that  effect.  "Today  the 
weather  is  fine,  the  roads  are  smooth  and  well  packed 
down,  and  I  -can  carry  just  as  many  blocks  as  I  can 
pile  onto  my  sled.  In  two  weeks  there  may  be  a  thaw, 
or  snowdrifts,  or  a  spell  of  stinging  cold,  or  a  run  of 
sickness  in  the  family.  I  would  rather  take  them  now 
and  stand  the  breakage  myself.  After  I  get  them  home 
they  can  cure  just  as  well  in  my  yard  as  yours. " 

And  so  the  blocks  were  taken  out  immediately. 
Not  many  blocks  were  broken,  but  such  as  they  were 
the  loss  was  willingly  borne  by  the  farmer,  for  he  had 
done  the  hauling  in  time  which  would  otherwise  have 
been  almost  a  total  loss,  over  good  snow  roads,  doing 
the  hauling  with  a  sled,  which  is  much  easier  to  load 
and  easier  to  haul  than  a  wagon,  and  the  blocks  were 
on  hand  ready  to  begin  work  as  soon  as  the  first  robin 
appeared. 

From  the  standpoint  of  the  block  manufacturer, 
too,  the  transaction  was  a  most  satisfactory  one.  It 
helped  him  to  keep  his  plant  running  during  the  cold 
season  without  unduly  crowding  the  yard;  it  helped 
to  distribute  his  yard  labor  over  a  longer  period,  and 
as  the  farmer  had  the  money  in  the  bank  from  the 
sale  of  his  fall  crops,  and  was  glad  to  take  advantage 
of  a  small  discount,  it  helped  the  manufacturer  to  keep 
up  the  financial  end  of  his  business. 


THE  PERFECTION   CONCRETE  STAVE  SILO 


PERFECTION  CONCRETE  STAVE  SILO  COMPANY 

516  CLAPP  BUILDING.  DES  MO1NES.  IOWA. 

There  is  only  one  way  to 
manufacture  concrete,  and 
that  is  by  the  "Wet-Mix" 
process.  Our  Perfection  Con- 
crete Stave  Silo  Stave  is  made 
by  the  "Wet-Mix"  process; 
the  staves  are  cast  in  moulds 
with  an  aggregate  of  one 
of  cement,  two  of  sand,  and 
three  of  gravel  or  crushed 
rock,  and  when  cured,  pro- 
duce a  strong,  non-porous 
product  and  present  a  hand- 
some appearance. 

Our  "all  steel"  large  door 
system  appeals  to  the  farmer 
and  silo  users.  We  sell  our 
moulds  outright;  we  make  no 
charge  for  royalties;  there  is 
no  "blue  sky"  or  exclusive  ter- 
ritory connected  with  our 
proposition.  You  pay  for 
what  you  get.  In  another 
part  of  this  book  is  a  com- 
plete description  of  our  silo. 
CONCRETE  WORKERS 

Get  into  the  silo  business. 
It  furnishes  splendid  profits; 
it  is  a  growing  business.  The 
silos  you  erect  this  year  will 
be  for  many,  many  years  to 
come  "silent  salesmen"  for 
you.  When  you  go  into  the 
concrete  stave  silo  business, 
get  the  best.  Get  a  system 
that  permits  making  the  staves 
by  the  "wet  process";  that 
permits  mortar  to  be  placed 
between  the  joints  of  every 
stave;  that  will  give  you  a 
malleable  door  frame  with  an 
all  steel  door  and  steel  ladder 
combination;  a  silo  without  a 
word  of  criticism  and  easy  to 
erect,  and  with  splendid  profits 
to  the  contractor.  Write  us 
for  information,  and  we  will 
gladly  send  you  our  literature. 
Excellent  terms  of  payment  to 
responsible  people. 


The  Polk  System 


OF 


Concrete  Silo  Construction 


(MONOLITHIC) 

PATENTED  OCTOBER  23.   1906 
PATENTED  DECEMBER  29.  1908 


Polk  Genung  Polk  Co.,  Inc.,      Fort  Branch,  Ind. 

INVENTORS  AND   MANUFACTURERS 

Opportunity  Eventually  concrete  will  displace  all  other 
*  material  used  in  silo,  water  tank,  and 
grain  storage  construction.  Agricultural  schools  and 
experiment  stations,  bankers  and  insurance  companies  are 
backing  concrete  silo  building.  They  are  backing  the 
POLK  SYSTEM  because  it  renders  a  distinct  service  in 
silo  construction.  Farmers  have  become  prejudiced  in 
favor  of  concrete  silos  because  of  their  ultimate  cheapness 
and  of  the  lasting  service  they  render.  In  the  field  of  silo 
construction  lies  the  greatest  opportunity  of  the  American 
contractor  today. 

The  contractor  who  is  equipped  with  a  POLK  SYSTEM 
machine  and  POLK  SYSTEM  methods  can  fully  guarantee 
any  building  he  erects.  He  has  the  assurance  of  a  big, 
successful  experience  behind  him.  He  knows  that  his 
work  will  please  far  beyond  expectation. 

Facilities  The  new  PPLK  SYSTEM  factory  with  its 

modern  equipment  enables  us  easily  and  eco- 
nomically to  manufacture  machines  with  every  single 
excellence  that  years  of  experience  have  proved  desirable. 
Not  a  single  expense  has  been  spared  that  will  help  to 
lower  the  cost  of  producing  POLK  SYSTEM  machines  and 
equipment  and  still  maintain  the  high  POLK  SYSTEM 
standard  of  quality.  We  are  putting  on  the  market  today 
the  most  thoroughly  designed  'and  the  most  durable 
machine  that  can  be  made  for  the  erection  of  monolithic 
concrete  silos. 

Polk  System  Silos  Are  Not  Built  of  Pieces 


THE     POLK      SYSTEM      MACHINE 


and  They  Cannot  Go  To  Pieces 


THE    POLK     SYSTEM     MACHINE 

Description  The  POLK  SYSTEM  is  in  reality  a  com- 
pletely detailed  plan  for  all  kinds  of  cir- 
cular monolithic  concrete  construction.  It  specifies  mix- 
tures and  proportions,  it  keeps  the  contractor  abreast  with 
the  times,  it  reduces  construction  costs  and  insures  a 
definite  progress  each  day,  and  it  makes  provision  for  the 
safety  of  laborers.  More  than  all  of  these,  it  insures  to 
the  farmer  a  flawless  structure  which  will  keep  his  silage 
secure  against  every  known  foe  of  good  silage.  The 
POLK  SYSTEM  is  much  more  than  a  mere  machine. 

Machine  The  POLK  SYSTEM  machine  is  an  all  steel 
equipment  for  the  erection  of  circular  mono- 
lithic concrete  structures.  It  has  been  developed  with  two 
things  in  mind — ease  of  operation  and  the  production  of 
absolutely  flawless  structures.  The  POLK  SYSTEM, 
machine  automatically  keeps  the  walls  plumb,  does  away 
with  an  elaborate,  complicated,  risky  system  of  scaffold- 
ing, imposes  no  strain  upon  the  section  of  wall  already 
built,  and  so  unifies  and  simplifies  construction  that  any 
intelligent  workman  can  easily  erect  the  most  perfect, 
monolithic  structure  on  earth. 

The  unifying,  simplifying,  protected  principle  of  the 
POLK  SYSTEM  machine  is  the  use  of  a  centermast.  This 
centermast  is  erected  at  the  center  of  the  floor  of  the 
structure  and  is  carefully  plumbed  by  means  of  guy  wires 
attached  to  the  top.  It  is  a  4-inch  steel  pipe  provided 
with  a  series  of  transverse  holes  to  receive  a  heavy  steel 
pin.  This  pin  supports  a  widely  flanged  collar  which 
serves  to  support  the  jack  by  which  the  forms  are  lifted. 

Resting  upon  the  jack  is  a  hub,  consisting  of  a  flanged 
base  collar  and  a  top  dished  collar  connected  by  a  central 
pipe  of  sufficient  diameter  to  work  easily  over  the  center- 
mast.  From  the  base  collar  of  this  hub  radiate  steel  Tees 
which  are  supported  from  the  upper  collar  by  adjustable 
hanger  rods  with  chain  clevises. 

The  wall-forming  forms  are  made  in  two  widths — four 
and  five  feet.  Each  form  consists  of  eight  separable  sec- 
tions, each  of  which  is  reenforced  and  stiffened  by  a  steel 
angle  frame  around  the  edges.  The  inner  and  outer  steel 

Polk  System  Machines  Render  the  Service 


THE    POLK     SYSTEM     MACHINE 


wall  forms  HIV  care- 
fully rolled  and 
tested  for  exact  cur- 
vature. They  are 
rigidly  bolted  to  the 
radiating  steel  Tees. 
The  outer  sections 
are  bolted  together 
at  their  ends  thru 
holes  in  the  frames. 
The  inner  sections 
are  similarly  fas- 
tened together,  but 
they  carry  a  steel 
wedge  between  them, 
the  lifting  of  which 
allows  them  to  swing 
free.  The  fact  that 
both  inner  and  outer 
forms  are  securely 
bolted  to  the  rigid 
steel  Tees  insures 
perfect  curvature 
and  alignment  for 
every  portion  of  the 
wall'. 

For  placing  the 
concrete  in  between 
the  forms  a  V-shaped 
dumping  bucket  is 
used.  This  bucket  is 
supported  by  a  crane 
pivotally  attached  to 
the  centermast  di- 
rectly above  the  top 
collar  of  the  hub.  It 
can  be  easily  swung 
to  any  part  of  the 
wall  space.  It  is 


Polk  System  Silos  Are  Indestructible 


THE    POLK    SYSTEM     MACHINE 

hoisted  by  means  of  a  rope  and  series  of  pulleys  so  arranged 
that  the  hoisting  force  is  applied  horizontally  from  with- 
out the  structure.  A  small  opening  thru  which  the  hoist- 
ing rope  works  is  cut  in  the  wall  near  the  bottom  of  the 
first  fill  of  concrete.  When  the  bucket  has  been  hoisted 
it  is  coupled  to  the  carrier  on  the  crane  by  means  of  a 
hinged  hook.  Then  it  is  swung  to  any  part  of  the  wall 
space  desired. 

The  scaffolding,  both  inner  and  outer,  is  swung  from 
the  steel  Tees  which  project  some  distance  beyond  the 
wall. 

fl  .  .  The  operation  of  the  machine  is  very  simple. 
UperatlOn 


forms  are  set,  the  reenforcing  bars  are 
placed  in  position,  the  concrete  is  mixed,  hoisted,  dumped 
and  packed  between  the  forms,  and  allowed  to  set. 

On  the  next  morning  the  nuts  connecting  the  sections  of 
the  outer  forms  are  loosened,  the  steel  wedges  fixing  the 
sections  of  the  inner  forms  are  lifted,  and  both  inner  and 
outer  forms  swing  free  from  the  wall.  Then  by  means  of 
the  jacks  resting  on  the  widely  flanged  base  collar,  the 
whole  mechanism  is  lifted  until  in  position  for  a  new 
fill  and  the  forms  again  are  set  by  means  of  the  bolts  and 
the  wedges. 

The  actual  raising  of  the  forms  for  a  new  fill  does  not 
require  more  than  ten  minutes.  Though  some  POLK 
SYSTEM  contractors  have  successfully  placed  two  fills  a 
day  during  hot,  dry  weather,  one  fill  >a  day  is  the  most 
satisfactory  rate  of  progress. 

Arlvnnf  arr  The  POLK  SYSTEM  machine  automatically 
Advantage*  keeps  the  wall  of  regular  thickness,  true  to 
a  circle  and  perfectly  plumb.  It  does  away  with  an 
always  risky  system  of  scaffolding  and  allows  no  strain 
on  the  "green  wall."  It  is  especially  adapted  for  high 
work.  It  also  provides  a  rapid  and  economical  means  of 
hoisting  and  depositing  concrete  in  the  form.  Besides  all 
of  this  the  contractor  can,  with  the  standard  POLK 
SYSTEM  machine,  build  any  sort  of  circular  reenforced 
concrete  work,  such  as  grain  storage  bins,  coal  pockets, 
smoke  stacks  and  water  tanks,  besides  the  silos  that  the 
farmers  are  calling  for.  _ 

Everybody  Believes  in  the  Polk  System 


THE    POLK     SYSTEM     MACHINE 

T       .          .   i  Knoxville,  Tenn.,  Jan.  16th,  1915. 

testimonial p0ik-Genung-Polk  Co.,  Ft.  Branch,  Indiana. 

Gentlemen: — In  answer  to  your  letter  of  the  llth  inst. 
I  am  very  willing  indeed  to  advise  you  concerning  my 
experience  with  the  POLK  SYSTEM. 

The  three  Polk  System  machines  bought  June  1,  1914, 
ran  steadily  the  remainder  of  the  season  and  netted  me  a 
splendid  profit.  I  attribute  no  little  of  my  success  to  tha 
certainty  with  which  your  machines  do  their  work.  Actual 
construction  costs,  after  applying  your  schedule  to  local 
conditions,  ran  close  with  my  schedule — so  I  know  just 
"where  I  was"  all  the  time.  The  depreciation  on  my 
equipment  was  negligible.  My  one  best  job  was  a  con- 
crete water  tower  124  ft.  high  which  I  built  with  one  of 
my  Polk  System  machines. 

This  year  inquiries  for  silos  are  coming  so  fast  I  am 
quite  sure  the  demand  will  be  greater  than  I  can  supply 
with  three  machines  and  will  have  to  buy  more  machines. 
I  can  plainly  see  that  this  permanent  silo  business  offers 
big  opportunity  for  contractors  and  I  am  glad  I  adopted 
the  ' '  line. ' '  Yours  truly, 

J.  A.  HIGGS. 

iiiT  .       The  POLK  SYSTEM  machine  is  made  of  the 

Warranty  best  material  obtainable  and  by  the  most 
skillful  mechanics  in  the  business.  Every  single  part  of 
the  machine  is  tested  before  leaving  the  factory.  The 
POLK  SYSTEM  machine  is  warranted  to  stand  up  to  the 
hardest  handling  without  breakage  of  any  kind.  The 
entire  resources  of  the  POLK  SYSTEM  and  the  whole 
POLK  SYSTEM  reputation  stand  back  of  every  single 
POLK  SYSTEM  machine. 

If  there  are  points  about  the  POLK  SYSTEM  that  are 
not  clear  in  your  mind,  kindly  allow  us  to  clarify  them. 
If  you  want  more  complete  information,  if  you  want  to 
know  what  our  contractors  are  accomplishing,  told  in  the 
words  of  the  contractors  themselves,  we  shall  gladly  fur- 
nish such  information  and  such  testimonials  at  your 
request.  Prices  will  be  furnished  for  delivery  to  any  rail- 
way point  in  the  United  States,  Canada  or  Mexico,  or  to 
any  port  for  export  trade. 

Polk  Genung  Polk  Co.,  Inc.,  Fort  Branch,  Indiana 


The  Hurst  Silo 


Patented  1902,  1904,  1914 


THE  CHAS.  B.  HURST  COMPANY 

Established  1904 

819-829  Exchange  Ave.,  Union  Stock  Yards 

CHICAGO,  ILL. 
Chillicothe,  O.  Live  Stock  Exchange  Bldg.,  Kansas  City,  Mo 

Prrkdurf  We  are  *^e  owners  of  tne  Hurst  Eeinforced  Concrete 
irUUULl  Block  Silo  Patents  and  sole  distributors  of  Hurst 
Patent  Gravity  Mass  Block  Molds  for  casting  these  Hurst  Silo 
Blocks. 


Op«rrinfrinn 


Silos  are  built  of  reinforced  concrete  blocks 
made    in    Hurst    Patent    Molds    using    the    poured 
The  Silo         system.      The   Blocks   are   23%    inches   long,    11% 
inches  high  and  4  inches  thick;  are  dense,  water- 
proof and  have  tremendous  crushing  resistance.     Each  block   has 
running   through   it   two   steel   rods    %    inches   thick.      These   rods 
have  their  ends  out  turned  at  right  angles  in  recesses  in  the  ends 

of  the  block,  as'  shown  in  Figure  3, 
No.  10.  They  are  curved  to  form  a 
perfect  circle  in  any  desired  circum- 
ference. 

The  blocks  are  laid  in  cement 
mortar  same  as  any  building  block. 
The  only  difference  is  in  the  rein- 
forcing and  locking  device.  Each 
circle  of  blocks  when  laid  in  the 
wall  forms  a  circular  chain  of  which 
each  block  with  its  reinforcement  is 
the  long  link.  When  blocks  are  set 
steel  links  are  placed  over  the  ends 
of  the  reinforcing  bars,  tension  ap- 
plied and  then  filled  with  cement. 
(See  Figure  3,  No.  10,  and  Figure  2.) 

In  the  above  manner  Hurst  Silos 
are  erected.  For  closer  detail  see 
Figure  3.  When  walls  are  complete, 
a  plaster  i/4-inch  thick  of  one  part 
cement,  two  parts  sand,  one-fifth 
hydrated  lime  is  applied,  making  a 
smooth,  waterproof  interior,  which 
insures  perfect  settling  and  keeping 
of  ensilage. 


HURST  SILOS  ARE  SOLD  EVERYWHERE  UNDER  A  WRITTEN  GUARANTEE 


THE    HURST     SILO 


Hurst  Silo  Molds    Hurst  Patented  Gravity  Mass  Block  Molds 
are  furnished  in  sets  of   ten   molds  each, 

having  a  capacity  of  two  hundred  blocks  per  day.  They  are  made 
of  light  steel  of  great  strength  and  are  practically  indestructible. 
Each  mold  consists  of  two  sides,  two  sets  of  division  plates,  clamps 
for  locking  molds,  and  core  covers.  The  sides  of  the  mold  are  of 
pressed  steel,  fitted  with  hollow  pressed  steel  cores,  which  hold  the 
reinforcing  rods  in  position  when  the  blocks  are  poured. 


Each  mold 
makes  10 
blocks  at  one 
filling  —  full 
size  or  half 
blocks  which 
are  used  at 
the  doors. 


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3.  awry  emrs  s  REJNfD/fCEMwr 

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c  ff&fsromvG  mo 


0.  SLOT  CWER. 
£  CUWED  STttL  /wmTXK 
f  ADJUSTABLE  CLAMfS. 


Simple,  Durable,  Practical  and 
Economical 


The  manufac- 
ture and  sale 
of  the  Hurst 
Silo  is  a  com- 
mercial proposition,  and 
will  enable  you  to  work 

twelve    months    in    the    year,    therefore,    our    proposition    should 
interest  you. 

A  small  investment  in  equipment  will  take  care  of  an  immense 
amount  of  business,  and  insure  quick  returns. 

For  more  than  eleven  years  Farmers  and  Stockmen  have  recog- 
nized the  Hurst  Silo  as  a  safe  investment  and  an  ornament  to  the 
farm. 

Eleven  years  and  not  a  failure— That 's  the  Record.  The  Hurst 
System  of  reinforced  concrete  construction  reduces  to  the  minimum 
time,  labor,  expense  and  competition. 

We  have  some  more  openings  for  live,  responsible  parties,  but 
they  are  going  fast.  Don't  put  it  off,  but  act  now.  Write  for 
particulars  and  catalog. 


You  Can  Make  Hur.t  Silo  Block,  in  the  Dead  of  Winter 


THE    HURST    SILO 


Operation 

1 — Bolt  every 
4  feet  for 
fastening 
roof. 

2— Step  lad- 
der. 

3 — Bolt  every 
3  feet  for 
fastening 
chute. 

4 — Door,  door 
frame,  door 
ladder 
steps. 

5— How  lad- 
der steps 
lay  in  mor- 
tar joints. 

6 — Eeinf  ore- 
ing  rods. 

7 — Sectional 
interior 
view  show- 
ing rein- 
forcing 
rods  and 
links  in 
blocks,  also 
the  smooth 
plaster  fin- 
ish wall  on 
the  inter- 
ior. 

8 — Concr  et e 
floor.  Hurst 
Silos  can 
be  built 
with  or 
without 
this  con- 
crete bot- 
tom. 

9 — F  o  u  n  d  a  - 
t  i  o  n  ex- 
tending be- 
low frost 
line. 

10 — Shows  reinforcing  rods  ready  for  steel  link, 
link  in  position,  tension  applied  to  rods  and 
finally  reinforcing  rods  covered  to  prevent 
corrosion. 

Make  Your  Blocks  in  Your  Plant,  Er.ct  Them  on  the  Job 


THE     HURST     SILO 


These  Prominent  Men  and  Institutions 
Use  and  Endorse  Hurst  Tanks  and  Silos 

L.  F.  SWIFT 

President,  Swift  &  Co. 
O.  W.  LEHMAN 

The  Fair  Store,  Chicago 
THE  ELMENDORF  FARM 

Lexington,  Ky. 
W.  E.  PINNEY 

Banker,  Valparaiso,  Ind. 
ILLINOIS  STATE  FAIR  ASSOCIATION 

Springfield,  HI. 
M.  W.  SAVAGE 

Owner  of  the  Famous  Dan  Patch 
XORTH  OAKS  STOCK  FARM 

Jas.  J.  Hill,  Proprietor 
P.  W.  CLIFORD 

Railroad  Contractor,  Valparaiso,  Ind. 
CHARLES  KELLY 

Pres.  National  Live  Stock  Commission  Co. 
S.  P.  STEVENS 

Sales  Manager,  Reid,  Murdoch  &  Co. 
JAMES  BROWN 

Head  Buyer,  Armour  &  Co. 
M.  WOLFE  ' 

Broker,  Union  Stock  Yards,  Chicago 
W.  H.  LEAZENBY 

Banker,  Bethany,  Mo. 
L.  B.  COCKRELL 

Banker,  Winchester,  Ky. 
THOMAS  JOHNSON 

Pres.  Lorain  Coal  &  Dock  Co.,  Columbus,  O. 
NORTHERN  INDIANA  LAND  CO. 

Demotte,  Ind. 
CAVE  VALLEY  LAND  AND  CATTLE  CO. 

Peoria,  HI. 
THE  POLK  SANITARY  MILK  CO. 

Indianapolis,  Ind. 
CALDWELL  &  SON 

Burlington  Jet.,  Mo. 

B.  C.  RHOME 

Pres.  of  North  State  Bank,  Ft.  Worth,  Tex. 
E.  E.  BETTS 

Supt.  Transportation,  C.  &  N.  W.  R.  R. 
G.  A.  STEPHENS 

Pres.  Moline  Plow  Co. 

C.  D.  THOMPSON 

Trenton,  Mo. 

It  Will  Cost  You  Nothing  To  Investigate. 

Thirty  Silos  Were  Built  for  One  Man.     All  Were  Hurst'* 


Reichert  Circular  Adjustable 
Metal  Molds 

Reichert  Mfg.  Co.,  Inc. 


1436-1440  Booth  Street 


Milwaukee,  Wis. 


PRODUCT: 

Reichert's  circular  adjustable  equipment,  consisting  of 
metal  molds  and  accessories  for  all  kinds  of  circular  mono- 
lithic concrete  construction;  Reichert  Metal  Molds  (Pat- 
ented) for  any  type  or  size  of  concrete  construction. 

SCOPE  OF  USE  FOR  CIRCULAR  ADJUSTABLE 
EQUIPMENT. 

Reichert's  Metal  Molds 
are  adapted  for  use  in  Gen- 
eral Concrete  Construction 
of  Silos,  Elevators,  Cis- 
terns, Railway  and  Water- 
tanks,  Barns,  Milk-houses, 
Coal-pockets,  etc.,  etc. 
ADVANTAGES: 

Reichert's  Molds  are  suc- 
cessfully operated  with 
common  labor;  can  be  used 
either  with  or  without  a 
round  or  square  chute; 
adjustable  to  any  diame- 
ter or  wall  thickness;  use 
less  room  in  transportation 
or  storage;  any  height  of 
wall.  Instead  of  having  an 
angle  iron  on  the  horizontal 
edges  a  band  iron  is  riveted 
to  the  horizontal  edges, 
which  allows  the  molds  to 
take  the  required  arch  of 
various  circles.  The  bands 
are  set  back  on  one  mold 
and  project  on  the  other, 
thus  making  a  lap  joint. 
This  lap  joint  making  a 
smooth  wall  and  off-sets  or 
'  ridges  cannot  be  made. 


Reichert's  standard  molds  have  been  successfully  operated 
on  structures  varying  from  6  ft.  0  in.  to  40  ft.  0  in.  in 
diameter;  from  2  ft.  to  85  ft.  in  height,  and  wall  thickness, 
varying  from  3  in.  to  1 8  in. 

The  same  unit  mold  since  1905.  This  record  means — 
the  endurance  of  an  idea,  the  permanent  satisfaction  of  a 
definite  design. 

OPPORTUNITY: 

Stop  and  consider  what  one  Reichert  Adjustable  Equip- 
ment can  do.  Some  farmers  need  big  silos,  others  want  them 
made  smaller.  With  a  Reichert  outfit  you  can  satisfy  them 
all  with  no  extra  outlay.  One  equipment  does  it  all. 

TESTIMONIAL: 

Ballinger,  Texas,  May  19,   1915. 

*  *  *  I  am  having  great  success  with  my  forms, 
building  six  feet  easily  on  a  twenty-foot  silo,  each  day. 

Silo  building  is  taking  a  boom  in  the  county  and  I  have 
all  I  can  possibly  do. 

Respectfully, 

Chas.  Eisenhuth. 

ROOF  MOLD: 

The  dome  roof  is  the  most  unique  design  of  any  style  of 
roof  ever  placed  on  a  concrete  silo.  The  Reichert  Roof 
Mold  consists  of  curved  segrnents  which  rest  on  the  silo 
wall  and  are  locked  to  a  hub,  or  ring,  at  the  top.  The 
angles  of  the  separate  sections  fit  into  this  hub,  or  ring, 
thus  locking  the  entire  equipment  together.  The  segments 
of  the  roof  can  be  packed  closely  together  and  loaded  in  a 
small  space  in  moving  from  one  job  to  another.  The  roof 
molds  include  the  complete  cornice  mold  and  a  mold  for  a 
dormer  window. 

REMARKS: 

We   are   willing   to    go   further   than   merely   sending   you 

our  litera- 
ture, prices, 
etc.  We  will 
gladly  show 
you  the  op- 
eration o  f 
these  molds 
right  on  the 
job  or  in 
our  factory. 
Once  seen, 
you'll  have 
none  others 
but  the 
Reichert. 


CHAS.  H.  SWAN 

"Superior  Lock"  Stave  Silo 

The  latest  and  most  up-to-date  stave  silo  on  the  market 

The  Chas.  H.  Swan  Circular  Staves 

The  Chas.  H.  Swan  ''Superior  Lock"  Staves  are  30  inches 

long,  10%  inches  wide,  2y2 
inches  thick,  and  are  circular 
to  conform  to  the  circle  of  the 
silo,  having  a  continuous 
tongue  and  groove  around  the 
stave  completely  locking  with 
6  other  staves.  With  the 
tongue  and  groove  or  shoulder 
joint  each  stave  has  a  true 
bearing  with  each  other,  and 
make  a  perfectly  smooth  silo 
inside  and  out,  and  with  the 
staves  made  on  a  circle  it 
makes  the  silo  perfectly  round 
and  one  of  the  easiest  to  erect. 
A  heavy  galvanized  band  or 
hoop  encircles  each  tier  of 
staves.  In  erecting  the  Chas. 
H.  Swan  "Superior  Lock" 
Stave  Silo  no  expert  help  is 
necessary  as  the  staves  set  up 
as  easily  as  setting  up  toy 
blocks. 

Chas  H.  Swan 

Labor  Saving  Stave  Machine 

The  machine  for  making  the 
Chas.  H.  Swan,  "Superior 
Lock"  Staves  is  the  last  word 
in  mould  construction.  All 
parts  of  the  mould  are  perfectly 
milled  with  special  milling 
cutters,  the  rear  section  of  the 
mould  is  securely  fastened  to 
the  base,  the  front  section  is 
hinged  to  the  base  and  swings 
down,  the  ends  are  hinged  to 
the  rear  section  and  swing  out 
and  when  closed  are  locked  to 
the  front  section  with  heavy 


malleable  clasps,  the  mould  can  be  easily  adjusted  to  make 
different  curved  staves.  This  machine  was  designed  by  Chas. 
II.  Swan  with  a  view  of  giving  the  contractor  a  labor  saving 
machine,  one  that  is  simple  in  construction,  with  few  oper- 
ations, and  one  that  can  be  used  with  an  automatic  tamper. 
One  of  these  machines  is  capable  of  constructing  600  perfect 
staves  daily. 


contractor  who  wishes  to  engage 
in  the  best  paying  propositions  of  the 
day;  one  that  will  pay  a  larger  percentage  of  profit  on  your 
money  than  you  can  receive  from  any  other  source;  a  busi- 
ness that  is  not  here  for  a  day,  but  one  that  is  here  to  stay, 
and  getting  better  each  year — then  begin  at  once  to  manu- 
facture and  erect  " Superior  Lock"  stave  silos. 
Write  for  complete  information  about  this  up-to-the-minute 
stave  silo,  and  get  our  big  money  making  proposition.  We 
are  sure  it  will  please  you.  Write  today. 


Swan  Concrete  Stave  Silo  Co. 

Cassopolis         ...          Michigan 


Winner   Opening    Silo    Roof 


Mr.  Concrete  Man,  are  you 
fully  abreast  of  the  times? 
Have  you  felt  the  commercial 
pulse,  the  wants  and  needs  of 
people  in  every  requisite  of 
the  silo  you  are  now  selling? 
For  instance,  take  the  roof 
you  are  selling  and  installing 
on  your  silos.  Is  it  such  as 
you  can  honestly  and  earn- 
estly recommend  to  your  pa- 
trons? Whether  it  be  wood, 
iron  or  concrete,  if  it  is  a  sta- 
tionary roof  it  is  badly  out  of 
harmony  with  silo  construc- 
tion progress, — the  wants  and 
needs  of  the  farmer. 

Listen!  You  sell  your  cus- 
tomer a  concrete  silo, — splen- 
did structure,  yet,  if  you  rec- 
ommend and  sell  him  a  sta- 
tionary roof,  you  are  doing 
him  an  injustice.  You  are 
compelling  him  to  use  only 
75%  of  his  silo.  Is  It  Right? 

Progress — The  last  word  in 
the  silo  world— THE  WINNER 
EXTENSION  ROOF  —  allows 
the  farmer  to  use  every  cubic 
inch  of  his  silo  space.  Adds 
25%  to  the  capacity  of  the 
silo.  The  WINNER  EXTEN- 
SION ROOF  gives  light,  fresh 
air,  ventilation,  convenience 
during  filling  time;  gives  per- 
fect protection  to  silo  and  en- 
silage; easily  installed  on  silo, 
and  easily  opened  and  closed. 

You  owe  it  to  yourself — you 
owe  it  to  the  men  whose 
money  pays  for  the  silos  you 
build,  that  you  give  them  an 
opportunity  to  use  every  foot 
of  silo  you  sell  them.  The 
WINNER  EXTENSION  ROOF 
does  this, — you  should  recom- 
mend and  sell  it.  The  farmer 
needs  and  wants  the  EXTEN- 
SION ROOF. 

We  make  the  WINNER  EX- 
TENSION ROOF  just  fit  and 
right  for  your  particular  silo. 
To  legitimate  builders  and 
dealers  we  allow  a  neat  profit. 
Write  us  for  our  proposition. 


SILO  SPECIALTY  MFG.  CO. 

423  West  on  Bldg.    :-:      Clinton,  Iowa 


Build  for  Permanency 


The  silo  which  defies  time  and 
elements  is  the  concrete  silo. 
Years  may  come  and  go  but  the 
concrete  silo  will  stand  as  a 
symbol  of  20th  century  perma- 
nent construction  ideas.  Yet  99% 
of  the  present  concrete  silos 
have  one  great  weakness, — THE 
DOOR  FRAME  AND  DOOR. 
It  is  crude,  ill-fitting,  cumber- 
some, and  really  inadequate  for 
its  purpose. 

Perhaps  your  silo  door  and 
frame  are  not  as  they  should  be. 
L,ook  into  the  latest  and  most 
scientific  door  frame  constructed, 
— the  AIR-TITE  all  steel  door 
frame.  With  it  you  can  ap.. 
proach  your  prospective  cus- 
tomer and  say:  "With  my  silo 
you  get  the  best  and  most  prac- 
tical door  frame  constructed." 
Consider  These  Points:  The  silo 
door  is  solely  for  the  purpose  of 
discharging  silage  as  needed. 
That  this  may  be  done  quickly 
and  with  the  least  possible  la- 
bor, the  door  must  be  continu- 
ous. The  AIR-TITE  is  continu- 
ous. You  build  your  silo  air 
tight  because  the  admittance  of  air  to  silage  will  spoil  it.  Then, 
should  not  the  door  be  as  tight  as  the  silo  wall?  The  AIR-TITE 
door  is  so. 

You  construct  your  silo  to  stand  the  test  of  time.  Should  not 
your  frame  and  doors  be  likewise?  The  AIR-TITE  frame  is  all  steel 
— inflexible,  unbreakable,  defying  time  and  elements  like  King  Cons 
crete.  But  more, — your  customer,  the  farmer  wants  simplicity, 
ease  of  operating,  etc.  All  this  he  finds  in  the  AIR-TITE.  No  felt, 
no  paper  packing,  no  freezing  of  door  to  frame.  Just  a  whole  lot 
of  srood  things  about  the  AIR-TITE  that  you  should  know.  Our 
booklet.  "Modern  Silo  Ideas,"  tells  you  about  it.  Write  for  it. 


Silo  Specialty  Mfg.  Co.,  c2™ 


423  Weston  Bldg. 
-  IOWA 


Monsco  Equipment 

For  Building  Concrete  Silos,  Grain  Bins  and  Tanks 

Monolithic  Silo  and  Construction  Company 

351-3  Peoples  Gas  Building,  Chicago,  Illinois 


PRODUCT — Builders  of  Molds  and  Equipment  for  the 
construction  of  Monolithic  Silos. 

DESCRIPTION — Monsco  Molds  are  built  very  heavily  of 
16  g-a.  black  steel  sheets  in  all  standard  sizes.  The  molds 
are  made  in  two  sections,  each  3  feet  high,  and  each  circle 
is  divided 

into  segments  , 

of  convenient 
size.  The 
molds  are  re- 
inforced with 
%"  steel  an- 
gles and 
channels 
welded  to  the 
sheets  to  in- 
sure rigidity. 

The  chute 
form  is  an 
integral  part 
of  one  of  the 
segments  and 
is  adjusted  to 
proper  position  by  means  of  transverse  turnbuckles. 

With  each  equipment  comes  a  scaffold-hoist  and  bucket. 
The  scaffold  is  raised  at  will  by  two  cast-steel  worm-geared 
winches  attached  to  the  center  mast.  This  equipment  does 
away  with  building  false  work  of  any  kind. 

OPERATION — The  operation  of  Monsco  Molds  has  been 
so  simplified  to  make  it  easy  for  even  common  labor.  Each 
mold  is  BO  divided  to  make  every  segment  convenient  in  size 
and  weight  for  easy  handling  and  interchangable.  Three 
feet  of  wall  is  poured  at  a  time.  Six  feet  a  day.  Next  day 
the  lower  3  foot  section  is  released,  raised  and  set  ready  for 
pouring.  This  section  clamps  onto  the  lower  three  foot 
section  which  is  filled  with  concrete,  set  sufficiently  to 
eliminate  the  possibility  of  a  wall  fracture.  The  molds  are 


entirely  independent  of  the  center-mast.  This  does  away 
with  constant  plumbing  of  the  center-mast  every  time  the 
molds  are  raised.  The  scaffold  and  hoist  are  also  raised  to 
points  of  advantage  on  the  steel  center-mast. 

OPPORTUNITY — In  the  Monsco  system  the  farmer  is 
given  a  continuous  door  (one  easily  installed  and  removed) 
a  concrete  chute — two  items  the  up-to-date  farmer  positive- 
ly demands. 

With  the  Monsco 
equipment  cold- 
drawn  steel  mesh 
reinforcement  is 
used.  This  type  of 
reinforcement  is  in- 
finitely superior  to 
bar  or  rod  reinforce- 
ment, as  it  makes 
the  wall  reinforced 
uniformly  through- 
out. On  our  own 
work  we  use  38-Inch 
width  mesh,  thus 
giving  an  oppor- 
tunity to  lap  2 
inches  on  each 
course.  This  gives 
you  strong  talking 
points  to  farmers  on 
strength  as  well  as 
permanence. 

OUR  SPECIALTY— Why,  ask  the  farmers,  don't  you  build 
a  concrete  roof  on  the  silo?  That's  just  the  question  we  ask. 
Owners  of  Monsco  Molds  are  getting  more  for  the  silos 
they  build  and  also  save  the  cost  of  buying  a  steel  roof. 
Their  Monsco  Roof  Molds  enable  them  to  produce  excellent 
roofs.  This  mold  can  be  erected  in  90  minutes  and  dis- 
mantled and  removed  in  60  minutes.  Ask  us  about  it  when 
talking  molds. 

REMARKS — Our  copyrighted  instruction  sheets  are  mailed 
to  every  customer  as  soon  as  the  order  is  booked.  These 
instructions  cover  every  possible  detail,  and  we  leave  noth- 
ing to  guess  work  or  experimenting  on  the  part  of  the 
operator.  You  can't  go  wrong  with  Monsco  Molds.  Write 
for  our  latest  literature.  We  have  splendid  catalogs  on  the 
silo  proposition  as  well  as  our  equipment.  Ask  for  it. 


Monolithic  Silo  &  Construction  Company 


351-3  Peoples  Gas  Bldg., 


Chicago,  Illinois 


Perfect  Reinforced   Silo  Block 

Perfect  Reinforced  Cement  Silo  &  Cistern  Co.,  Delaware,  0. 

PERFECT  SILO  BLOCKS  are  shaped  to  the  radius  of  the  silo,  and  are  24 
inches  long,  12  inches  high  and  4  inches  thick.  The  blocks  lay  up  large,  re- 
ducing the  cost  of  laying,  while  on  account  of  the  thin  wall  they  are  not  too 
heavy  to  handle. 

Each  block  Is  reinforced  with  two  iron  rods  running  lengthwise,  6  inches 
apart.  Each  rod  is  looped  6  inches  from  the  end.  These  loops  in  the  rod 
coincide  with  the  holes  that  are  formed  edgewise  through  the  block  1  Inch 
in  diameter  and  6  inches  from  either  end.  In  laying  the  blocks  these  1-inch 
openings  are  filled  with  cement  grout  and  a  rod  or  dowel  pin  is  pressed 
through  the  soft  cement,  connecting  the  two  blocks.  Each  pin  is  inserted  in 
such  a  way  that  it  passes  entirely  through  one  block  and  half  way  through 
the  block  above  and  the  one  below. 

This  provides  for  a  continuous  lateral  rein- 
forcement around  the  silo  every  6  inches,  and 
the  dowel  pins  that  run  through  the  blocks 
from  the  bottom  to  the  top  of  the  silo  form  a 
vertical  reinforcement  every  12  inches. 

A  strip  of  netting  composed  of  7  longitud- 
inal and  12  vertical  steel  wires,  imbedded  in 
the  block  just  beneath  the  outer  surface,  is 
designed  to  prevent  any  liability  of  cracking 
of  the  face  of  the  block.  This  virtually  forms 
a  steel  covering  in  the  block  near  the  outer 
surface  of  the  entire  silo. 

To  unite  the  blocks  and  to  overcome  the 
outward  pressure  or  thrust,  a  two-ply  twisted 
steel  cable  of  No.  8  wire  is  laid  outside  of  the 
dowel  pins  in  the  mortar  between  the  courses 
of  blocks,  in  grooves  provided  for  that  pur- 
pose. The  ends 
of  these  cables 
ire  looped  about 
a  continuous 
gas  pipe  which 
extends  from 
the  top  to  the 
bottom  of  the 
structure, 
through  the 
blocks  each  side 
of  the  doorway. 
This  gas  pipe 
also  passes 
through  holes 
in  the  ends  of 
the  ladder 
rounds  thus  the 
cable  and  the 
ladder  rungs  in 
connection  with 
the  gas  pipe 
form  acomplete 
r  e  i  nforcement 
around  the  silo 
from  the  top  to 
the  bottom, 
throughout each 
foot  of  its 
height,  which 
r  e  i  nforcement 
is  four  times 
more  than  suf- 
ficient to  with- 
stand the  pres- 
sure of  the  en- 
silage, but  it  is 
so  made  in  or- 
der to  withstand 
the  heat  of  a 
possible  flre. 


This  illustration  shows  the  con- 
tinuous doorway  with  ladder  rungs 
across  same  every  alternate  course  of 
blocks,  and  the  manner  of  connecting 
the  ladder  rungs  and  the  twisted  steel 
cable  by  means  of  the  continuous  gas 
pipe  passing  through  the  dowel  pin 
holes  in  the  blocks  each  side  of  dooi- 
way.  It  also  shows  the  rabbet  formed 
in  the  edge  of  the  doorway  blocks 
to  receive  the  doors.  The  dotted 
lines  at  the  right  indicate  positions  of 
gas  pipe,  dowel  pins,  cable,  netting 
and  loop  wires. 


Perfect"     Silos    Are    Never    Adversely    Criticizde 


Playford  Stave  Silos 


Playford  Mfg.  Co.,  Inc. 


Elgin,  Illinois 


Those  who  live  in  the  states  of  Minnesota,  North  and  South 
Dakota,  Iowa,  Nebraska  and  Wisconsin,  and  wish  to  acquire  an 
agency  or  manufacturing;  and  sales  rights  in  same,  address  the 
MINNESOTA  CEMENT  CONSTRUCTION  CO.,  LONG  PRAIRIE, 
MINN. 

PRODUCT — A  reinforced,  ribbed,  slushed  concrete  stave  silo  of 
great  strength  and  matchless  durability  and  efficiency. 

DESCRIPTION 
—  The  staves 
are  slush  mold- 
ed in  special 

molds.  Each  End  yiew  of  Staves,  Showing  Off-set  Hoops  and  Form  of 
stave  is  thor-  Construction  and  Recess  for  Pointing  Outside, 
oughly  reinforced  with  bars.  Each  stave  has  a  4V4  rib  that  adds 
still  greater  strength.  Each  stave  has  a  concave  and  convex 
edge  and  a  lock  on  the  ends.  The  staves  interlock  when  erecting. 
The  Playford  staves  are  five  times  stronger  than  the  ordinary 

stave.  Absolutely  waterproof. 
Outside  pointing  prevents  the 
staves  from  "checking"  and  re- 
lieves the  strain  on  the  staves, 
thereby  making  it  unnecessary 
to  double-hoop.  Hoops  can't  sag. 
The  Playford  Silo  embodies  the 
latest,  up-to-date  knowledge  and 
experience  in  silo  building.  Be- 
ing a  new  silo,  we  are  not  forced 
to  cling  to  old  ideas.  We  pro- 
duce a  silo  that  is  strikingly  dif- 
ferent. The  Playford  will  enable 
you  as  a  contractor  to  offer  an  A 
No.  1  business  proposition  to  the 
farmer. 

OUR  PROPOSITION — Be  the  con- 
tractor who  will  be  able  to  give 
the  farmer  a  real  business  propo- 
sition. The  demand  already  ex- 
ists— trade  will  come  to  you 
easily  and  quickly.  There  is  12 
solid  years  of  silo  experience  be- 
hind our  proposition.  We  have 
plenty  of  capital  and  the  equip- 
ment to  "make  good"  in  every 
direction.  It's  the  broadest  and 
most  workable  kind  of  a  deal 
ever  put  out.  Now  is  the  chance 
to  secure  the  choicest  territory. 
Write  to-day. 


Interlocking  Cement  Stave  Silos 

Interlocking  Cement  Stave  Silo  Company 

414-17  FLYNN  BLDG. DES  MO1NES,  IA. 

The  inventions  used  and  developed  by  this  Company  make  It  possible 
for  our  lessees  to  construct  concrete  silos,  water-tanks,  and  other  build- 
ings, of  any  desired  size,  and  to  sell  them  to  the  farmer  at  a  price  which 
approximates  the  cost  of  an  ordinary  good  wood  structure.  This  is  only 
possible  because  of  the  great  simplicity  of  our  system,  and  the  fact  that 
we  only  use  one  stave  in  any  construction,  regardless  of  whether  It  be  a 
silo  eight  feet  in  diameter,  or  twenty-eight  feet.  Our  system  does  not 
require  a  manufacturer  to  keep  on  hand  a  number  of  different  sized  staves 
to  be  used  in  different  sized  structures,  and  therefore  this  not  only  simpli- 
fies his  business,  but  reduces  the  up-keep  expense  to  a  minimum.  One 
of  our  machines  is  capable  of  constructing  five  hundred  staves  per  day, 
and  each  stave  is  just  as  perfect  as  is  the  gearing  of  a  watch. 

The  erecting  of  a  silo,  or  any  other  structure  requiring  a  multiplicity 
of  these  staves,  is  as  simple  as  is  the  mating  of  toy  building  block*  by  a 


child.  This  is  made  possible  by  the  absolute  perfection  of  the  machine 
which  we  use  for  the  manufacturing  of  our  staves,  a  cut  of  which  is 
shown  herewith. 

Our  INTERLOCKING  feature  is  such  that  there  Is  not  a  Joint  in  our 
completed  structure,  but  that  is  strengthened  by  an  encircling  band,  and 
this  is  accomplished  with  a  lesser  number  of  bands  than  Is  used  by  any 
other  construction  known.  We  will  give  you  a  full  and  satisfactory  guar- 
antee concerning  everything  regarding  our  system. 

If  you  are  desirous  of  engaging  in  a  business  which  Is  the  llveat  and 
most  flourishing  business  there  is  in  the  country  today,  and  want  a  proposi- 
tion which  will  pay  you  a  larger  percentage  on  your  money  than  you  can 
receive  from  anything  else,  write  us  today,  and  we  will  thoroughly  explain 
our  proposition. 


Forms  for  Monolithic  Silos 

MARTIN  CONCRETE  FORM  CO.,  Ottawa,  Kan. 

Product     We  are  manu^act;urers  °^  the  Martin  Steel  Forms 

for  Monolithic  Silos;  also  Culvert  Forms  in  Circle 

Arch  and  Flat  Top  Patterns. 

Descrintion    The  Martin  Sil°  Form  is  made  of  sheet  8teel 

*-. which  is  held  in  place  and  adjusted  to  either 

12,  14,  16,  18,  and  20  foot  diameter  sizes.  The  adjustment  is  made 
by  means  of  turn-buckles.  The  form  is  held  in  place  by  angle  irons 
radiating  from  the  center  and  braced  from  the  bottom  to  the  top 
of  the  form.  The  form  is  raised  by  means  of  jacks  used  on  the 
upright  reinforcing  rods. 

Adaptability 

When  you  buy  a  Martin 
Steel  Form  for  Mono- 
lithic Silo  work  you  are 
buying  a  form  that  has 
all  the  good  features  of 
other  silo  forms  and  one 
other  feature  that  gives 
you  the  advantage  over 
users  of  other  makes. 
This  feature  is  its  ad- 
justability. With  a 
Martin  Form  you  can 
build  silos  of  five  differ- 
ent dimensions.  It  is  not 
iifct-ss.-ti-y  to  have  live 
separate  equipments. 

a  Martin  Steel  Form  in  hand,  your 
opportunity  is  assured.  Its  wide  range,  its 
perfect  operation  and  its  uninterrupted  success  is  bound  to  help 
you  in  the  silo  business.  Eemember  one  investment  in  Martin 
Forms  puts  you  in  a  business  where  others  have  invested  money  for 
new  forms  every  time  a  new  size  silo  was  in  demand. 

Let  us  send  you  our  catalog  and  prices.     We  are  certain  they 
will  interest  you. 

Ask  About  Our  ADJUSTABLE  CULVERT  FORMS 


Playf  ord  Cement  Stave  Silo 

Cement  Stave  Silo  Company          Des  Moines,  la. 
Patentees  and  Manufacturers 


Product 


A   system   of   erecting   silos    of   cement    staves    which 
enables  you  to  build  them  in  any  diameter  and  height 


at  a  lower  cost  than  any  other  permanent  silo,  and  a  system  for 

making  the  cement  staves. 

yi  .     ..  The   machine   for  mak- 

UescnptlOn      ing.    the    cernent    staves 

is   on   the   order   of   a  block   machine,    is 

portable  and  is  operated  with   the  same 

ease.       This    machine    builds    staves    30 

inches   long-,   10   inches   wide,   2%    inches 

thick    with    concave    and    convex    edges 

that  make  perfect  socket  joints. 

In  construction  the  PLAYFORD  CE- 
MENT STAVES  are  put  up  vertically,  in- 
terlocking at  the  half,  with  joints  her- 
metically tsealed  and  reinforced  every  15 
inches  with  steel  hoops  on  the  outside: 
This  makes  a  smooth,  thin,  rigid,  air- 
tight and  strong  enough  wall  to  with- 
stand load  and  storm  pressures,  and 
frost.  Open  joints  are  allowed  every  10 
inches  for  expansion  and  contraction  to 
eliminate  cracked  walls  from  heat  or 
frost. 


Advantages™^ 

PLAYFORD  CEMENT 
STAVE  you  do  not 
limit  your  operations 
to  silos  only.  Water 
tanks,  utility  houses, 
culverts  and  even 
straight-wall  barns 
are  built  with  these 
staves.  Don't  you  see 
your  opportunity  here? 

Opportunity 

chance  to  make 
money.  Better  write 
us  for  particulars  and 
terms  on  our  STAVE 
MACHINES. 


Playford  Cement  Stave  Silo  is  the  Kin*  of  Silos— Ask  the  farmer 


The  HOBBS 

Block  Machine 


Will  Do  More 

and 
Better  Work 


Success  comes  to  the 
block  maker  who  is 
prepared  to  fill  any  order 
for  any  building.  You  absolutely  must  have  a 
machine  that  makes  a  great  variety  of  sizes  at  small 
expense.  Recognize  the  wisdom  of  discarding  the 
old  and  installing  the  new  machine  if  it  will  do 
more  and  better  work. 

Order  a  Hobbs  on  trial  and  if  it  is  not  the  best  built  block 
machine  you  ever  saw,  if  our  composition  plates  do  not  make 
the  most  natural  rock  face,  if  it  is  not  the  fastest  to  change 
and  operate,  if  it  will  not  make  the  wettest  block,  if  it  is 
not  entirely  satisfactory,  then  return  the  machine  and  we 
will  not  only  pay  all  freight,  but  your  cartage  as  well. 

First  get  our  catalog. 

THE  HOBBS  CONCRETE  MACHINERY  CO. 

1445  West  Boulevard  DETROIT,  MICH. 


Lansing    Company 

LANSING,  MICHIGAN 


WAREHOUSES 


NEW   YORK 
288-289  West   St. 

CHICAGO 
169  West  Lake  St. 

MINNEAPOLIS 
330  North  First  St. 

KANSAS   CITY 
1415  West  10th  St. 

SAN  FRANCISCO' 

338  Brannan  St. 
PHILADELPHIA 

Willow  and 
North   American    Sis. 

BOSTON 
78    Cambridge    St. 
Charlestown    Dist. 

Branch    Factory 
PARKIN,  ARK. 

— Lansing  Dove  Tail  Silo  Block  Machine. 

A  machine  designed  to  make  blocks  of  unusual  strength 
to  resist  the  pressure  of  the  ensilage. 

Is  furnished  in  almost  any  diameter  wanted,  being  made  in 
12,  14,  16  and  18-foot  sizes,  and  the  blocks  for  any  of  these  sizes 
can  be  spaced  a  little  differently  for  making  larger  or  smaller 
diameters.  For  example,  the  14-foot  size  will  answer  for  12,  14 
and  16-foot  diameter. 

Mn*»liinn — *'s  made  of  heavy  gray  iron  castings,  consisting  of 
iu<H.iiinebage  and  moid.  The  mold  consists  of  two  end  plates, 
face  plate  and  back  plate  and  cores.  A  complete  outfit  is  fur- 
nished, including  sample  pallet,  tamper  and  striker  for  leveling 
the  blocks. 

Two  different  size  machines  are  made — 8x9x16  and  8x10x16. 
We  recommend  the  8x10x16  for  larger  size  silos.  Both  machines 
make  blocks  7%  inches  high,  and  eight  wide  and  16  inches  long. 
Onarafi/in  — Tne  operation  of  producing  a  block  on  our  Silo  Block 
ujierdiiuil  machine  is  very  simple.  All  you  have  to  do  is  to 
operate  it  like  any  block  machine. 


Showing  the  inter-tier  and  inter-block 
tie  used  on  our  silo  blocks. 

~~ The  reinforcing  of  the  blocks  is  provided  for  in  the 
manufacture  of  the  blocks,  the  finished  block  having 
grooves  across  the  top  in  which  wire  reinforcing  is  placed. 

It  will  be  noticed  that  the  dovetail  opening  sets  over  a  small, 
round  opening  and  into  this  opening  is  poured  >soft  cement.  When 
this  hardens,  it  thoroughly  binds  the  different  tiers  of  blocks,  as 
well  as  each  individual  block,  together  into  a  continuous  concrete 
silo.  The  combination  of  the  three  reinforcements  makes  it  abso- 
lutely the  strongest  and  best  silo  on  earth,  having  the  advantage 
of  hollow  wall  with  the  strength  of  the  solid  wall. 
BomavL-e — The  Lansing  Dovetail  Silo  Block  machine  is  made  of 
ivcnicu  ivs  the  best  grade  of  materials  and  guaranteed  t  be  free 
from  defects  due  to  faulty  material  or  workmanship.  Further 
details  and  prices  furnished  on  request. 


Peerless  Silo  Molds 


Monolithic  Concrete  Silo  Build- 
Ing  is  highly  profitable  if  the 
right  equipment  is  used.  The 
RIGHT  one  is  the  one  with  the 
largest  daily  capacity,  making 
the  greatest  possible  speed  with 
the  least  effort  and  least  possi- 
ble expense.  This  is  accomplished 
with  a  Peerless  Silo  outfit,  the 
ORIGINAL  Steel  Molds  for  silo 
building. 

The  principal  advantages  of 
the  Peerless  System  and  Molds 
are: 

1.  A      CHUTE      CONTINUOUS 
WITH   MAIN   WALL.      See  U.    S. 
Letters      Patent      No.      1,122,329. 
Other   patents  pending. 

2.  FLEXIBLE  TYPE  of  molds 
— adjustable   to    different    diame- 
ters but  retaining  the  rigidity  of 
a,  standard  mold. 

3.  UNIQUE  SIMPLICITY  of  mechanism  and  operation;  elimi- 
nating all  cumbersome  or  troublesome  equipment  such  as  center- 
mast,  guy  ropes,   wires,   etc. 

4.  SALES  METHODS,     (a)  We  GIVE  you  EXCLUSIVE  RIGHT 
to  build   Peerless  Silos  within  a  specified  district.     This  valuable 
concession   costs  you  nothing:.     The  only  molds  sold  on  this  plan, 
(b)    We  sell  an   interest   in  molds  and   build   in  partnership   with 
option  to  purchase  our  interest. 

5.  We  use  the  same  equipment  we  sell. 
WRITE   US   FOR   PEERLESS   PARTICULARS. 


%'  Daily  Capacity  Mold; 
Capacity,   2   Rings   3'   each. 


Monolithic    Concrete   Barn    and   Silos,    Lexington,   Ky.,    Built   with 
Peerless   Silo  and  Wall   Molds. 

New  Enterprise  Concrete  Machinery  Company 


910  First  National  Bank  Bid*., 


CHICAGO,  ILL. 


Hoosier  Silo  Extension  Roof 


AND   METAL  CHUTE 


Sheet  Metal  Specialty  Co.       Goshen,  Ind. 


Manufacturers 


Product  ^  metal  sil°  r00^  which  can  be  opened  up  out  of  the 
^— ^^—  way,  when  filling  the  silo,  and  when  so  opened  forms 
an  extension  to  the  top  of  the  silo,  which  takes  care  of  the  settling 
of  ensilage. 

Descrintion  The  roof  consists  of  three 
inscription  parts.  a  base>  a  double 

section  segment  and  a  single  section  seg- 
ment. The  base  is  fastened  to  the  silo 
by  means  of  strap  irons.  The  segments 
are  made  of  crimped  galvanized  sheet 
metal  and  both  single  and  double  section 
segments  are  hinged  alternately  to  the 
base.  The  double  section  segments  have 
two  wings  hinged  on  each  side,  which  fold 
one  inward  and  the  other  outward.  When 
opened  and  locked  they  form  a  complete 
circle,  like  shown  in  illustration. 


Roof  Open 


The   farmer  'once   shown 
will  see  these  p,0intlS  in 

favor  of  a  HOOSIER  roof: 

A    roof    that    is    not    in    the    way    when 
filling  the   silo. 

A    roof    that    makes    it    possible    to    use 
all  your  silo. 

A  roof  that  will   fit  any  silo  and  work 
satisfactorily. 

A  roof  that  measures  the  same   on   the 
inside   as   your   silo,   therefore;    the   silage 
is   the  same  volume  as  that  in  your  silo. 
A  roof   that  is  void   of  cross   arms 
and    braces     to     hinder    your    silage 
from  settling. 

R*»marlr«Tne      HOOSIER      SILO 

nemarKS  EXTENSION  ROOF  win 

help  cinch  the  sale  of  a  silo.  Just 
try  it  on  the  next  farmer  and  see 
how  interested  he'll  become.  Only 
men  like  him  will  appreciate  the 
value  of  this  roof,  because  you  <give 
him  more  for  his  money. 

Better  get  posted  on  this  HOOSIER 
SILO  EXTENSION  ROOF,  Mr.  Con- 
crete Silo  Builder.  It  will  help  you 
wonderfully  in  your  business.  Ask 
for  our  catalogue. 


The   HOOSIER   Roof   is   not  only    right    in    theory    but  Guaranteed    Practical 


Buckeye  Silo  Roofs 


Gambrel  Roof  With  Dormer  Window. 

We  manufacture  a  full  line  of  sheet  metal  equipment  for 
concrete  silo,  such  as  Gambrel,  Third  Pitch  and  Extension 
Roofs.  Also  Metal  Chutes,  Ladders  and  Ladder  Rungs. 

Buckeye  All  Steel  Silo  Door  For  Concrete  Silos 


MANUFACTURED    BY 

The  Thomas  &  Armstrong  Co. 
London,  Ohio 

For  sale   by 
B.   L.   BEVINGTON  MCH.  CO. 

549  W.  Washington  Blvd.  CHICAGO,  ILLINOIS 

— AND — 

THE  PIERCE  CO. 
1102  Waldheim   Bid*.  KANSAS   CITY,   MO 


"MEDUSAIZE"  YOUR  SILOS 


BY  USING 


Medusa  Gray  Portland  Cement 
Medusa  Waterproofing 
Medusa  Waterproofed  Cement 


YOU  want  your  silo  to  last  for  generations 
and  you  want  it  impervious  to  water  and 
dampness.  When  you  use  Medusa  products 
you  are  using  the  same  materials  that  have 
been  adopted  by  the  U.  S.  Government  for 
coast  defense  work,  breakwaters,  etc.,  and 
this  should  convince  the  most  skeptical  of  their 
superiority.  Don't  take  any  chances  by  allow- 
ing "something  just  as  good"  to  be  used. 


BUILD  OF  MEDUSA 

AND  MAKE  YOUR  SILO  A  MONUMENT  TO  YOUR  GOOD  JUDGMENT 


Write  for  prices,  sam- 
ples and  illustrated  and  de- 
scriptive catalogs  contain- 
ing tests  and  testimonials. 


Oandusky  I  ortland  Cement  Co. 

SANDUSKY,  OHIO 


On  a  Bag  of  Cement 
Stands  for  a  Record 
of  24  Years  of  Quality 

When  you  buy  lumber  you  can  see  the  qualityl 
for  yourself;  when  you  buy  Portland  Cement, 
you  must  rely  on  the  maker  and  the  dealer.^ 
There  are  different  kinds  and  grades  of  "Port- 
land" Cement.  Don't  risk  ruining  your  job 
with  poor  cement. 


ALPHA 


THE  GUARANTEED 
PORTLAND 

CEMENT 


is  warranted  by  us  and  by  all  ALPHA  dealers 
to  more  than  meet  the  U.S. Government  stand- 
ard. The  Government  has  used  ALPHA  ex- 
tensively for  fortifications,  sea  walls,  dams,  etc. 
The  ALPHA  chemists  test  the  product  every 
hour,  keeping  it  up  to  the  very  top  in  uniform- 
ity, fineness  and  binding  power. 

Ask  the  ALPHA  Dealer  for  further  details  and  for 
a  copy  of  the  large  ALPHA  book,  showing  how  to  build 
silos  and  make  scores  of  farm  and  home  concrete  improve- 
ments. If  you  don't  know  the  ALPHA  dealer,  write  us, 
mentioning  what  you  are  planning  to  build.  Address 
Dept.  B. 

Alpha  Portland  Cement  Company 

General  Offices:  Easton,  Pa.,  Sales  Offices:  New  York,  Chicago, 
Philadelphia,  Boston,  Pittsburgh,  Buffalo,  Baltimore,  Savannah 


An  Average  of  51 


visitors  each  business 
day  for  six  months 
called  at  this  demon- 
strating silo  erected  by 
the  Holmes  -  Harding 
Company  i  n  Sioux 
City,  Iowa,  with  AT- 
LAS PORTLAND 
CEMENT. 

There  seems  to  be 
quite  a  little  interest  in 
Atlas  Concrete  Silos — 
and  with  good  reason. 

THE  ATLAS  PORTLAND 
CEMENT  CO. 

New  York     Chicago    Philadelphia 
Minneapolis          Des  Moines 


Marquette  Portland  Cement 

"The  Certified  Cement" 

A    cement    of  certified 
quality  for  all  purposes 


Portland  Cement  is  a  mined 
After  the  rock  -s  blasted  from 

the  mine  it  is  conveyed  to  the  surface  of  the  earth,  where  it 
goes  through  the  various  processes  of  crushing,  burning,  pul- 
verizing and  curing,  until  it  is  ready  for  sacking.  Hourly  tests 
are  made  of  all  raw  materials  and  at  different  stages  of  manu- 
facture as  well  as  the  finished  product  to  insure  uniform  as 
well  as  the  best  quality.  Every  bag  of  Marquette  Portland 
Cement  is  guaranteed  to  conform  to  Standard  and  Government 
Specifications;  there  is  a  green  guarantee  tag  attached  to  every 
bag;  it  certifies  Marquette  quality. 

Packages  and  Territory 

strong  duck  bags  or  strong  paper  sacks  into  the  states  of 
Illinois,  Wisconsin,  Minnesota,  Iowa,  Indiana  and  Michigan. 
Prices  are  quoted  by  barrel;  four  bags  to  a  barrel. 


on  request  to  anyone  interested 
in  building  in  the  Middle  West. 
"Building  for  the  Future,"  a  book  containing  photographic 
proof  of  Marquette  achievements. 

"Concrete  in  the  Country,"  the  use  of  concrete  on  the  farm. 
"Concrete    Silos"    information    on    the   building  as    well   as 
filling  of  silos. 

Marquette  Cement    Mfg.  Company 

Marquette  Building  CHICAGO 

EVERY     BAG     OF    MARQUETTE    IS     GUARANTEED 


The  Ideal  Hoists 

Reversible    or    Non-  Re versi  b  le 

Made  by 

UNIVERSAL  HOIST  &  MFG.  CO. 
605  State  St.,  Cedar  Falls,  Iowa 


PRODUCT — We  are  manufacturers  of  the  world  known  Ideal  Hoists. 
Made  in  sizes  and  styles  suitable  for  all  purposes.     The 
hoist  described  here  is  most  suited  for  silo  construction. 

DESCRIPTION— The  Regular  Ideal  Hoist  is    mounted  on  an  8-foot 
frame  equipped  with  friction  band  brake  and  ratchet 
brake,  adapted   for   direct  hoisting,  single  platform  elevator,  derrick, 
etc.     It  will  handle  loads  up  to  1500  pounds. 

OPERATION — Ideal  Hoists  'are  equipped  to  be  operated  with  any 
make  of  Gas  Engine,  motor  or  other  power;  driving 
sprocket  wheels  and  chain,  or  belt  wheel  for  belt  drive  furnished  free. 
They  can  be  mounted  up  with  a  concrete 
mixer  or  other  machines  and  connected 
to  the  same  engine,  so  that  it  is  not  necessary 
to  buy  an  extra  engine  to  operate  the 
hoist.  The  simplicity,  ease  of  operation 
and  reasonable  price  of  this  hoist  has 
made  it  very  popular  among  contractors 
who  specialize  on  small  buildings,  silos,  etc. 

30  DAYS' FREE  TRIAL 

— All  Ideal  Hoists  are 
shipped  subject  to  ap- 
proval after  30  days 
trial.  They  are  guaran- 
teed to  fulfill  the  re- 
quirements in  every 
respect.  There  i  s  n  o 
risk  in  placing  your 
order  for  an  Ideal  Hoist. 
It  is  a  valuable  addition 
to  any  contractors' 
equipment  —  soon  pays 
for  itself  in  the  saving 
of  time,  labor  and  ex- 
pense. 

REMARKS— Further  information  in  regard  to  a  hoist  for  any  particu- 
lar kind  of  work  will  be  gladly  furnished.     We   build 
them  in  all  styles  and   sizes.     Ask  for  our  Catalog  and  prices  and 
state  what  work  you  want  to  do  with  a  hoist. 


The  Low  Down 

Concrete  Mixer 


ACCURATE 
AUTOMATIC 


The  feeding  device  on  this  machine  is  positive, 
accurate  and  automatic.  The  materials  are  forced 
into  the  mixing  trough  in  accurate  proportions  and 
even,  continuous,  unbroken  streams  which  guaran- 
tees a  finished  concrete  of  even  texture  without 
weak  or  lean  spots.  This  kind  of  a  mixture  is 
highly  essential  in  all  concrete  silo  construction. 
This  machine  has  a  capacity  of  from  4  to  12  cubic 
yards  per  hour.  It  is  constructed  entirely  of  mal- 
leable iron  and  steel.  Has  a  mixing  device  so  de- 
signed that  the  cement  is  thoroughly  incorporated 
with  the  aggregate. 


Write  for  descriptive  catalog  and  prices  to 

Elite  Mfg.  Co.  Ashland,  Ohio 


The  Knickerbocker  Co. 


Jackson,  Michigan 


Mfrs.  of 


Batch  and  Continuous 
Concrete  Mixers 


A  batch  machine 
with  stationary  meas- 
uring hopper,  equipped 
with  a  hoist  for  elevat- 
ing concrete  to  forms. 

Capacity  —  7  cu.  ft. 
loose  materials  per 
batch. 

Power — 4  H.-P.  Ideal 
or  Novo. 

Weight — 2,300  Ibs. 

Wheels — 16  and  22- 
inch. 

Capacity  of  hoist — 
500  Ibs. 

One  man  can  advantageously  operate  these  machines  and  produce 
sufficient  concrete  for  silo  requirements.  Where  more  capacity  is 
desired,  put  on  another  man.  Machines  furnished  with  wagon 
tread  when  required. 

No.  9  Coltrin — A  contin- 
uous machine  that  has 
mixed  concrete  for  every 
country  requirement. 

Capacity — 8  cu.  yds.  per 
hour. 

Power — 3  H.-P.  Ideal  or 
Novo. 

Weight— 1,900  Ibs. 
Wheels — 22  and  30  inch. 

Our  Machines  Combining 

Portability — Durability — Dependability 

Quickly  Save  Their  Cost 

The   Knickerbocker  Co. 


MINSTER 

Batch  Concrete  Mixers 

are  for 

Silo  and  Farm  Work 

they  are 

Handy — Rapid — Economical 


Low  Price— High  Quality 

Mixes  sand,  gravel  or  crushed  stone,  wet,  dry  or  any  way 
concrete  is  wanted. 

Easily  moved  from  place  to  place. 

Built  of  best  materials,  and  made  for  hard  continuous  service. 
Fully  guaranteed.  The  best  machine  you  can  get  for  your 
work.  Write  today  for  full  particulars  and  prices. 


THE  CUMMINGS  MACHINE  CO. 


SffiS 


FOR  SILO  WORK 


the  two  mixers  illustrated  on  this    page     have  fully  met 
the  exacting  conditions  of  good  concrete  silo  construction, 


The  Eureka 
Batch  Mixer 

holds  5  to  6  cu.  ft.  dry 
material   per  batch. 
Furnished    with    Side 
Loader,     Batch     Hopper, 
Wheelbarrow  Hopper, 
h.  p.  engine  operates  it. 
portability    and    compact, 
construction  are  commendable  features 
for  frequent  moves  over  rough  roads. 

The  Eureka  Continuous  Mixer 

shown  here  has  a  capacity  of  5  to  8 
cu.  yds.  an  hour.  It  is  well  adapted 
for  silo  work,  and  is  widely  used  for 
that  purpose. 

On  account  of  limited  space  here 
will  you  kindly  ask  for  catalog  and 
more  complete  information. 


EUREKA  MACHINE  COMPANY 

112  Handy  St.,  Lansing,  Mich. 


"The  Standard" 

Low  Charging 
Concrete  Mixer 

The  charging 
platform  of  "The 
Standard"  Mixer  is 
only  24-inches  high 
from  the  ground 
and  is  furnished 
with  the  outfit  (see 
illustration)  which 
makes  the  mixer 
easily  charged  di- 
rect from  wheel- 
barrows. This 
does  away  with  the 
necessity  of  building  high  platforms  or  the  use  of  dangerous  *ir*° 
loaders  which  cause  three-fourths  of  your  delays  and  breakdowns. 

The  large  opening  In  charging  end  of  drum  permits  constant 
inspection  of  batch  at  all  times  and  enables  you  to  determine  exact 
condition  of  same  before  discharging.  It  is  essential  to  get  good 
concrete  in  the  construction  of  Silos,  Tanks,  etc. 

The  illustration  below  shows  mixer  equipped  with  hoist  for 
elevating  conciete  or  other  uses  and  is  especially  adapted  for  con- 
struction of  Silos,  Towers,  Chimneys,  etc.  This  design  provides  the 
handling  of  mixed  concrete  in  an  elevated  position  without  requiring 
a  separate  hoisting  equipment.  The  mixer  and  hoist  are  driven  by 
the  same  engine  and  can  be  operated  together  or  independently  as 
desired. 

The  weight  of  "The  Standard"  Low 
Charging  Mixer  is  reduced  to  a  minimum 
on  account  of  its  simple  construction,  few 
working  parts,  etc.,  which 
allow  the  outfit  to  be  easily 
moved  from  one  location  to 
another.  These  machines 
are  built  in  capacities  of 
3  to  40  cubic  feet  per 
batch  and  complete  Cat- 
alog Xo.  22SB  will  be 
mailed  at  your  request. 


The  Standard  Scale  &  Supply  Co.,  Mfrs. 

1345-4?  Wabash  Ave.          243-245  Water  St.  136  W.  Broadway 

Chicago  Pittsburgh  New  York 

35  So.  4th  St.  1547  Columbus  Rd. 

Philadelphia  Cleveland 


The  Winner 

Model   "E"  4  and  6  Cubic  Ft.  Concrete  Mixer 
Made  by  The  Cement  Tile  Machinery  Co. 

408  Rath  St.,  Waterloo,  la. 


Description      — ^  special  concrete  mixer  with  hoist,  especially 
adapted  to  silo  builders.     A  simple  batch  mixer 
with  an  open  drum   that  does  the  mixing  always  in  sight.     Easily 
charged  and  more  easily  discharged. 

The  Winner  was  primarily  built  to  answer  the  requirements  of 
the  silo  contractor.  It  is  light  and  handy  to  move  through  the 
country  from  one  job  to  another,  has  the  mixer  and  hoist  all  com- 
bined in  one  machine.  Hundreds  of  operators  in  all  parts  of  the 
country  have  placed  their  O.  K.  on  this  type  as  a  silo  rig.  It  is  so 
simple  and  efficient 

The  Winner 
will  mix  con- 
crete as  well  as 
the  best  mixer 
on  the  market 
and  the  hoist 
will  not  be  in 
the  way,  or 
bother  the  oper- 
ator when  the 
mixing  is  being 
done.  The  hoist 
can  be  used  sep- 
arate, or  the 
mixer  separate, 
or  both  together 

and  neither  one  will  interfere  with  the  work  of  the  other.  You 
couldn't  buy  a  separate  hoist  for  anywhere  near  the  price  we  ask 
for  this  neat,  efficient  and  durable  little  rig. 

Write  for  our  Catalog  and  Prices. 


The  Winner 

With  or  Without  Hoist 
4  or  6  Cu.  Ft. 


The  Hoist  is  a  single   drum,   non-reversible  type. 


Anderson  Rotary  Mixer 


It's  a  One  Man  Control 


W.  H.  Anderson  Tool  &  Supply  Co. 

182  Brush  Street,  Detroit,  Michigan 

Arlantahilitv    Tne  Anderson  Rotary  Mixer  is  without  question 
/\Ud|liauillljr     tne  begj.  an(j  most  economically  operated  con- 


crete mixer  on  the  market  today,  particularly  adapted  to  the 
contractor  who  wants  a  portable  machine  for  silo  or  other  small 
jobs  requiring  a  capacity  of  75  to  80  cubic  yards  per  day. 

The  Anderson  Rotary  Mixer  is  a  one  man  con- 
trol.     The    operator    has    full    control   of    side 

loader,  water  and  discharge.    Mixer  is  furnished  with  wheelbarrow 

or  batch  hopper,  or  side  loader,  as  desired.     Also  with  or  without 

hoist.     Frame  and  truck  are 

made  of  steel.     Drum  is   36 

inches    in    diameter,    is    con- 
structed with  heavy  cast  iron 

heads,    with    slop    rings    on 

loading  and  discharging  ends 

cast    integral    with    head    to 

prevent  wasting  or  slopping 

of  material.    Wheels  are  pro- 
tected   by    mud    rings    from 

grit  and  mud.    The  blades  of 

the  drum  are  so  arranged  to 

give    a    thorough    mixing    of 

the  materials  in  a  minimum 

amount  of  time.    Has  a  steel 

driving  gear  of  solid  forged 

steel    with    hardened    roller 

steel  chain.     Novo  Engine. 


Guarantee 


The  Anderson  Rotary  Mixer  is  guaranteed 
against  defective  material  of  any  kind,  but  not 
the  replacement  of  broken  parts  when  these  parts  are  broken  by 
carelessness.  We  will  replace  any  defective  part  if  said  part  is 
forwarded  to  us,  prepaid  carrier,  for  our  inspection. 

We  have  studied  very  carefully  the  conditions  and 
^G  methods  of  the  contractors,  being  in  the  con- 
tractors' supply  business  for  44  years,  and  we  are  offering  this 
machine  to  you  backed  by  our  guarantee,  experience  and  reputa- 
tion. All  these  features  mean  a  great  deal  to  contractors  in  the 
saving  of  wages  alone.  The  one  man  control  feature  alone  will 
save  5  to  10  dollars  per  day  in  expenses  and  greatly  increase  the 
output. 


Ask  for  the  Anderson  Rotary  Mixer  Bulletin  107E. 


Jaeger  Big-an-Litle  Mixer 

_  "A  Mix  a  Minute  Kind"  _ 

Made  by    THE  JAEGER  MACHINE  CO., 

217  Rich  Street  Columbus,  Ohio 


RHV 

puy 


a 

a 


for  or  desire 


and  you  will  enjoy  every  pos- 
sible advantage  you  could  ask 
a  mixer,  especially  a  mixer  for  silo  or  other 
^  small  construction  work.   It 

mixes  a  batch  a  minute — 
5  to  6  cubic  feet — mixing 
always  open  to  thft  eye. 
Charging  and  discharging 
is  the  simplest  of  its  kind. 
Its  hoist  attachment  is  in- 
dispensable for  silo  work. 

If  you  want  an  efficient, 
economical  and  portable 
mixer,  get  a  Jaeger  "Big- 
an-Litle." 

The  Drum,  of  conical-shape,  rests  on  the  yoke 
and  revolves  around  the  axis,  which  is  held  by 
yoke  at  an  angle.  The  power  to  rotate  the  drum  is  taken  from  the 
drive  pinion,  which  has  its  bearing  in  the  center  of  one  end  of  the 
yoke,  making  it  possible  for  the  drum  to  be  discharged  while  re- 
volving. The  Power  to  drive  the  pinion  is  taken  from  the  engine 
by  means  of  gears,  which  thus  produces  a  positive  drive  with  no 
possibility  of  break-down.  The  Outfit  is  of  the  best  mechanical 
design  and  construction.  It  is  rigidly  braced  to  insure  greatest 
strength,  eliminate  all  strain  and  withstand  long-continued  rough 
usage,  with 
p  r  a  ctically 
n  o  outlay 
for  repairs. 

If  you  want 
speed,  steady 
service  and 
correct  mix- 
ing, get  a 
Jaeger  "Big- 
A  n  -  L,  i  1 1  e 
Mixer." 

Ask  the 
man  who 
uses  one. 


Catalog  Tells  Whj 


Archer  Special 

Concrete  Mixer 

Archer  Iron  Works 

34th  Place  and  Western  Avenue 

An   Ideal   Mixer   for   Silo   Construction 

The  big  problem  of  the  silo 
builder  -and  the  general  con- 
crete contractor  has  been  to 
obtain  a  really  portable  mixer, 
not  too  small  in  capacity  and 
yet  at  a  low  price. 

The  Archer  Special   Concrete 
Mixer    supplies     this     want     in 
every   respect.      The   placing   of 
the  weight  of  the  heavier  parts 
of  the  machine  over  the  wheels 
allows    the   mixer    to    be    easily 
lifted  at  the  platform  end  and 
moved      around      on      the      job 
without      trouble. 
When    moving    from 
one    job    to    another 
simply    hook     the 
platform     end     onto 
the    back    end    of    a 
wagon     and     "you're 
off."         For       Silo 
building  the  mixer  is 
specially         provided 
with  a  hoisting  drum 
direct    connected    to 
the  countershaft. 

The  mixer  has  a 
capacity  of  4%  cubic  feet  of  wet  concrete  per  batch  or  6  to  7 
cubic  feet  of  dry  material.  This  allows  a  daily  capacity  of  50  cubic 
yards  which  Is  the  amount  we  guarantee,  although  many  contractors 
have  greatly  exceeded  this  amount. 

The  Archer  Special  mixer  is  not  only  adapted  to  Silo  Building  but 
is  particularly  fitted  for  all  classes  of  concrete  work  such  as  Founda- 
tions, Sidewalks,  Concrete  Roads,  Culverts,  Bridges,  etc.  One  of 
the  chief  advantages  of  the  mixer  for  general  work  lies  in  the  End 
Discharging  feature,  which  makes  it  possible  to  spout  concrete  direct 
into  the  forms  in  most  cases  thus  saving  the  cost  of  wheeling. 

The  End  Discharge  together  with  the  Portability  or  easy  mov- 
ing feature  gives  the  machine  a  special  advantage  over  most  types 
of  small  mixers  intended  for  use  on  jobs  running  up  to  3,000  cubic 
yards  or  less.  While  mixing  costs  vary  according  to  the  layout  of 
the  jobs,  the  average  labor  cost  with  the  Archer  Special  has  been 
determined  to  range  around  40  cents  per  cubic  yard  of  concrete 
mixed  and  placed. 

Full  particulars  and  prices,  write  for  catalogue  E,  furnished  on 
request. 

The  Logical  Mixer  for  Contractors 


THOROUGHNESS 

Concrete  in  Silo  Construction  MUST  be  Thoroughly  Mixed. 

The  Blystone  Shovels,  which  insure  absolutely  perfect 
mixing  of  concrete  or  mortar.  Handle  dry  or  wet,  coarse 
or  fine  material. 


The  open  drum  enables 
the  whole  mixing  opera- 
tion to  be  watched  and 
controlled.  Extremely  easy 
to  clean.  No  attachments 
to  eat  up  power  and  get 
out  of  order.  Every  ounce 
of  power  mixes. 

Hopper  &  Son,  Manhat- 
tan, Kansas,  say:  "We 


now  have  in  use  five  of 
your  mixers  building  silos. 
We  find  it  a  very  conven- 
ient mixer  for  this  pur- 
pose. We  are  especially 
concerned  in  a  thorough 
mix,  light  weight  for  trans- 
portation and  moderate 
price.  In  all  these  re- 
spects your  machine  fills 
the  bill." 


OVER    1300   BLYSTONES    NOW  IN    USE 
INVESTIGATE    AT    ONCE 

BLYSTONE  MFG.  CO. 

140  Second  Street  Cambridge  Springs,  Pa, 


17  C  -  I  ^       \\7*  +*•  L*   Take  the  M  ajority 

r or  olio    Work  choice— the 

WONDER  MIXER 

with  AUXILIARYl  HOIST 


Specially  designed  for  Silo  builders,  this  combination  has  also 
proved  the  most  popular  all-around  mixing  and  hoisting  outfit  on  the 
market.  It  is  extensively  used  by  chimney  builders,  where  condi- 
tions similar  to  those  obtaining  in  silo  work  are  met.  It  is  simple, 
strong  and  dependable,  and  only  12  inches  longer  than  our  standard 
LITTLE  WONDER  "FIVE"  mixer,  and  the  hoist  adds  but  200 
pounds  in  weight. 

The  WONDER  has  2%  h.  p.  gasoline  engine  and  lifts  700  pounds 
at  45,  or  500  pounds  at  60  feet  per  minute.  Where  heavier  loads 
are  to  be  hoisted,  we  equip  with  4  V&  h.  p.  engine.  Cable  capacity 
250  feet  of  %-inch  cable.  Hoisting  drum  has  ratchet  and  pawl  for 
holding  load  at  rest,  or,  by  means  of  the  brake  it  can  be  "spotted" 
at  any  point  desired.  Side  Loader  can  be  added  to  this  machine  at 
time  of  purchase  if  wanted. 

The  Secret  of  Success 

in  silo  building  is  the  density  of  the  mix — its  air  and  water  tight 
quality.  Two  concerns  are  each  using  40  WONDERS,  and  several 
20  or  more  for  this  reason,  and  thousands  of  contractors  throughout 
the  country  testify  to  WONDER  superiority  in  every  essential  point 
of  mixer  construction. 

Send  for  Our  Special  Trial  Offer 

and  catalog  of  "The  Mixers  That  Make  the  Money"  before  deciding 
upon  any  mixer. 

Branch  offices  and  distributing:  depots  in  New  York,  Philadelphia, 
Chicago  and  a  dozen  other  large  cities,  also  100  agencies.  Write  for 
(lie  nearest  to  you. 

WATERLOO  CEMENT  MACHINERY  CORPORATION 

125  VINTON  ST.,  WATERLOO,  IOWA 

Mfrs.  Concrete  Mixers,  Traction  Paoers.Trench  Fitters  and  Contractors   Equipment 


Simplex  Continuous  Concrete  Mixer 

This  machine  combines  the  rolling  principle  of  mix  embodied  in 
all  Batch  mixers,  with  an  absolutely  accurate  measuring  device 
and  positive  force  feed.  The  revolving  cylindrical  drum  is  slightly 
tilted,  which  allows  for  a  rolling  mix  and  gravity  discharge.  The 
material  is  fed  into  the  mixing  drum  through  a  three  compartment 
hopper  equipped  with  a  measuring  device  and  force  feeding  attach- 
ment which  are  graduated  for  any  desired  proportion.  The  drum  is 
sixty  inches  long,  and  on  account  of  the  slight  tilt,  the  material 
falls  two  inches  toward  the  discharge  end  with  each  revolution. 
Water  is  applied  eighteen  inches  from  the  discharge  end,  providing 
for  a  21  time  dry  and  a  9  time  wet  mix  before  the  material  is 
discharged.  The  capacity  of  the  machine  is  regularly  from  one  to 
ten  yards  per  hour,  which  may  be  increased  to  twenty  yards  per 
hour.  It  is  equipped  with  3  h.  p.  engine. 

Simplex  Batch  Mixer 

This  machine  is  constructed  after  standard  principles,  the  drum 
having  special  cast  heads,  with  eight  gauge  boiler  plate  steel  shell. 
It  is  equipped  with  regular  or  batch  hopper,  and  made  in  either 
side  or  end  discharge  type.  Capacity,  eight  cubic  feet,  dry  mix. 
It  is  equipped  with  4  h.  p.  gasoline  engine. 

The  Miles  Manufacturing  Co. 

Jackson,  Mich. 


A  Baby  Grand  on  Silo  Work 

A  Continuous  Mixer  and  a  Single  Drum  Hoist  Combined 

HALL-HOLMES  MFG.  CO. 

509  OAK  STREET  JACKSON,  MICH. 


Operation  The 

-  tion  gives  a 
fair  idea  of  the  opera- 
tion of  a  Baby  Grand 
Mixer,  with  Single 
Hoist  Drum,  used  on  a 
silo  job.  The  contrac- 
tors are  Arnold  Nagel 
&  Co.,  Libertyville,  111. 


working  parts   are   completely   enclosed   in 
them  from  grit  and  dirt. 


Description  The 

-  Grand 
Mixer  is  universally 
recognized  as  the  best 
continuous  concrete 
mixer  for  all  purposes. 
It  eliminates  uncer- 
tainty. The  first  batch 
is  the  same  as  the 
last.  It  is  built  for 
hard  service  and  the 
cost  of  upkeep  is  prac- 
tically nothing  All 
steel  housing  to  protect 


If  >'ou  are 
bull  ding 

a  silo  or 
a  concrete  floor  in 
the  upper  story  of  a 
building,  a  hoist  on 
your  continuous  mix- 
er enables  you  to 
pour  a  steady  stream 
o  f  concrete.  The 
hoist  is  mounted  on 
the  frame  of  the  ma- 
chine and  operates 
with  or  independent 
of  the  mixer. 

Testimonial  :T..1; 

bought 

for  my  Baby  Grand 
has  given  perfect 
satisfaction.  Yours 
respectfully,  J.  L. 
Irving."  General 
contractor  and  build- 
er of  Area,  Lake 
County,  Illinois. 


ASK  FOB  CATALOG 


IDEAL  Concrete  Silo  Block  Equipment 

Ideal  Concrete  Machinery  Co. 

1304  Mo n mouth  Ave. 
Windsor,  Ont.  Cincinnati,  Ohio 


THE  PRODUCT— We  are  manufacturers 
of  the  famous  IDEAL  Concrete  Block 
Machinery,  both  for  silo  work  and 
straight  walls. 

THE  MACHINE— The  illustration  in 
the  center  of  the  page  shows  the 
IDEAL  Model  "A"  Silo  Block  Ma- 
chine, which  makes  blocks  for  silos 
having  a  5-foot,  7-foot  or  9-foot  radius. 
Any  standard 
face  design  can 
be  used.  The 
machine  is  sim- 
ple in  construc- 
tion and  swift  in 
operation.  The 
same  machine 
can  also  be  used 
in  making  blocks 


THE   SILOS— 

The  silos  possess 
every  advantage 
of  monol  i  t  h  i  c 
construe  tion 
with  the  addi- 
tional advant- 
ages of  hollow 
wall  construc- 
tion, which  in- 
sures a  more 
even  temperature 
inside  the  silo 
and  is  a  great  protection  for  ensilage  in  freez- 
ing weather.  Ideal  Silo  Blocks  have  a  very 
practical  arrangement  for  placing  the  rein- 
forcing (see  diagram).  Every  block  is  perfect 
and  true  to  curvature  inside  and  out  and  can 
be  inspected  before  placing  in  the  wall. 

LITERATURE — It  will  pay  you  to  get  our 
literature  and  specifications  on  the  IDEAL  Silo 
Block  equipment.  Send  for  them. 


"IDEAL" 

The  most  reliable  concrete  machinery 


for      houses, 
barns,  etc. 


.  , 


C/D 


\ 


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T  r»  «o  A    (cn^y,  o  'RA                                     General  Library 
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Berkeley 

